Title of Invention: ELECTRONIC NOTIFICATIONS OF USERS CONCURRENTLY INTERACTING WITH THE SAME FEED ITEM OF A SOCIAL NETWORK FEED Abstract: Disclosed are examples of systems, apparatus, methods and computer program products for providing electronic notifications that users are concurrently interacting with the same feed item of a social network feed. In some implementations, first data from a first user system can identify a first feed item of the feed as one with which a first user is interacting. It can be determined that a second user using a second user system is concurrently interacting with the first feed item. Based on the determinations, a notification can be sent to one or both user systems. The notification can include data indicating that the first and second users are concurrently interacting with the first feed item. Detailed Description: COPYRIGHT NOTICE A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the United States Patent and Trademark Office patent file or records but otherwise reserves all copyright rights whatsoever. TECHNICAL FIELD This patent document generally relates to social network feeds. More specifically, this patent document discloses techniques for providing notifications of users concurrently interacting with the same feed item of a social network feed. BACKGROUND “Cloud computing” services provide shared resources, applications, and information to computers and other devices upon request. In cloud computing environments, services can be provided by one or more servers accessible over the Internet rather than installing software locally on in-house computer systems. As such, users having a variety of roles can interact with cloud computing services. BRIEF DESCRIPTION OF THE DRAWINGS The included drawings are for illustrative purposes and serve only to provide examples of possible structures and operations for the disclosed inventive systems, apparatus, methods and computer techniques for providing notifications of users concurrently interacting with the same feed item of a social network feed. These drawings in no way limit any changes in form and detail that may be made by one skilled in the art without departing from the spirit and scope of the disclosed implementations. FIG. 1 shows a system diagram of an example of a database system 100 for providing notifications of users concurrently interacting with the same feed item of a social network feed, in accordance with some implementations. FIG. 2 shows a flow chart of an example of a method 200 for notifying a user that another user is interacting with a feed item of a feed of a social networking system associated with a database system, in accordance with some implementations. FIG. 3 shows a flow chart of an example of a method 300 for notifying a user that another user is interacting with a feed item of a feed of a social networking system, in accordance with some implementations. FIG. 4 shows an example of a user interface 400 with a feed item of a social network feed in the form of a graphical user interface (GUI) as displayed on a computing device, in accordance with some implementations. FIG. 5 shows an example of a user interface 500 with a social network feed and notifications in the form of a GUI as displayed on a computing device, in accordance with some implementations. FIG. 6 shows an example of a user interface 600 with a social network feed in the form of a GUI as displayed on a computing device, in accordance with some implementations. FIG. 7A shows a block diagram of an example of an environment 10 in which an on-demand database service can be used in accordance with some implementations. FIG. 7B shows a block diagram of an example of some implementations of elements of FIG. 7A and various possible interconnections between these elements. FIG. 8A shows a system diagram of an example of architectural components of an on-demand database service environment 900, in accordance with some implementations. FIG. 8B shows a system diagram further illustrating an example of architectural components of an on-demand database service environment, in accordance with some implementations. DETAILED DESCRIPTION Examples of systems, apparatus, methods and computer-readable storage media according to the disclosed implementations are described in this section. These examples are being provided solely to add context and aid in the understanding of the disclosed implementations. It will thus be apparent to one skilled in the art that implementations may be practiced without some or all of these specific details. In other instances, certain operations have not been described in detail to avoid unnecessarily obscuring implementations. Other applications are possible, such that the following examples should not be taken as definitive or limiting either in scope or setting. In the following detailed description, references are made to the accompanying drawings, which form a part of the description and in which are shown, by way of illustration, specific implementations. Although these implementations are described in sufficient detail to enable one skilled in the art to practice the disclosed implementations, it is understood that these examples are not limiting, such that other implementations may be used and changes may be made without departing from their spirit and scope. For example, the operations of methods shown and described herein are not necessarily performed in the order indicated. It should also be understood that the methods may include more or fewer operations than are indicated. In some implementations, operations described herein as separate operations may be combined. Conversely, what may be described herein as a single operation may be implemented in multiple operations. Some implementations of the disclosed systems, apparatus, methods and computer program products are configured for providing notifications that users are concurrently interacting with the same feed item of a social network feed. In a conventional social network feed environment, users can interact with a feed item such as a post or comment in different ways. But at any given time, users often are unaware of who else may be interacting with the same feed item, resulting in inefficiencies and unnecessary redundancy. By way of illustration, Pham is an engineer at Sell Fast, a software company that specializes in cloud-based software for selling various items. Sell Fast has thousands of employees at various locations around the world. Pham, located in the United States, is part of a global team of engineers responsible for developing a new cloud-based application that is going to be implemented in the near future. As the deadline for completion of the application nears, Zed the project manager has some important questions that need to be answered immediately. As such, Zed publishes a post with a list of 8 questions to a group feed of a social network used by the team at Sell Fast. All of the engineers who are part of Pham's team, including Anna, an engineer living in India, are members of the group and thus receive updates to the group feed. Both Pham and Anna are very busy and are trying to complete their respective tasks to complete the application before the deadline. Pham and Anna notice the list of 8 questions in their social network feeds at about the same time, and both are capable of answering the questions. Anna starts her response immediately and Pham begins writing a similar response 5 minutes later. After 30 minutes have passed, and as Pham is about to complete and publish his response, he notices in the group feed that Anna has published a comment on Zed's post with nearly the same answers Pham spent the last 30 minutes typing. Living across the world from each other, Pham knew that Anna was perfectly capable of answering the questions but assumed that Anna was asleep and not working. Otherwise he would have not spent 30 minutes composing his response. Some of the disclosed techniques can be implemented to generate electronic notifications to a first user that a second user is concurrently interacting with the same feed item with which the first user is interacting in a social network feed. By way of example, a graphical user interface (GUI) presenting a social network feed on a display of a user's smartphone, tablet, laptop, etc. can display a notification to the user that another user is interacting with the same feed item displayed in the GUI. In some implementations, the notification can display details of the interaction with the feed item. In an alternative scenario to that described above, as Pham is composing a response to the 8 questions, a pop-up window can be generated on his display screen to indicate Anna has viewed the feed item and/or is composing a response. For example, the notification can report: “Anna and Pham are viewing Zed's post”, and/or “Anna is typing a response to Zed's post.” In another scenario of a conventional social network feed, both Pham and Anna could assume that each other is going to write the response to the 8 questions. Based on their assumptions, neither Pham nor Anna responds, and Zed does not get the answers he needs in a timely manner, creating a bottleneck in the team's productivity. On the other hand, implementing some of the disclosed notification techniques, both Pham and Anna can assume that appropriate notifications would be generated if another user had viewed or begun responding to a post. As such, if a notification to Pham indicates only that Anna has viewed the feed item, Pham can assume that she is not preparing a response and can proceed in typing his response. Additionally, Anna and Joel, another engineer on the team, can be informed by notifications on their displays that Pham is typing a response. Some but not all of the techniques described or referenced herein are implemented using a social networking system. Social networking systems have become a popular way to facilitate communication among people, any of whom can be recognized as users of a social networking system. One example of a social networking system is Chatter®, provided by salesforce.com, inc. of San Francisco, Calif. salesforce.com, inc. is a provider of social networking services, customer relationship management (CRM) services and other database management services, any of which can be accessed and used in conjunction with the techniques disclosed herein in some implementations. These various services can be provided in a cloud computing environment, for example, in the context of a multi-tenant database system. Thus, the disclosed techniques can be implemented without having to install software locally, that is, on computing devices of users interacting with services available through the cloud. While the disclosed implementations are often described with reference to Chatter®, those skilled in the art should understand that the disclosed techniques are neither limited to Chatter® nor to any other services and systems provided by salesforce.com, inc. and can be implemented in the context of various other database systems and/or social networking systems such as Facebook®, LinkedIn®, Twitter®, Google+®, Yammer® and Jive® by way of example only. Some social networking systems can be implemented in various settings, including organizations. For instance, a social networking system can be implemented to connect users within an enterprise such as a company or business partnership, or a group of users within such an organization. For instance, Chatter® can be used by employee users in a division of a business organization to share data, communicate, and collaborate with each other for various social purposes often involving the business of the organization. In the example of a multi-tenant database system, each organization or group within the organization can be a respective tenant of the system, as described in greater detail below. In some social networking systems, users can access one or more social network feeds, which include updates presented as items or entries in the feed. Such a feed item can include a single update or a collection of individual updates. A feed item can include various types of data including character-based data, audio data, image data and/or video data. A social network feed can be displayed in a GUI on a display device such as the display of a computing device as described below. The updates can include various social network data from various sources and can be stored in an on-demand database service environment. In some implementations, the disclosed methods, apparatus, systems, and computer program products may be configured or designed for use in a multi-tenant database environment. In some implementations, a social networking system may allow a user to follow data objects in the form of CRM records such as cases, accounts, or opportunities, in addition to following individual users and groups of users. The “following” of a record stored in a database, as described in greater detail below, allows a user to track the progress of that record when the user is subscribed to the record. Updates to the record, also referred to herein as changes to the record, are one type of update that can occur and be noted on a social network feed such as a record feed or a news feed of a user subscribed to the record. Examples of record updates include field changes in the record, updates to the status of a record, as well as the creation of the record itself. Some records are publicly accessible, such that any user can follow the record, while other records are private, for which appropriate security clearance/permissions are a prerequisite to a user following the record. Updates can include various types of updates, which may or may not be linked with a particular record. For example, updates can be social media messages submitted by a user or can otherwise be generated in response to user actions or in response to events. Examples of social media messages include: posts, comments, indications of a user's personal preferences such as “likes” and “dislikes”, updates to a user's status, uploaded files, and user-submitted hyperlinks to social network data or other network data such as various documents and/or web pages on the Internet. Posts can include alpha-numeric or other character-based user inputs such as words, phrases, statements, questions, emotional expressions, and/or symbols. Comments generally refer to responses to posts or to other updates, such as words, phrases, statements, answers, questions, and reactionary emotional expressions and/or symbols. Multimedia data can be included in, linked with, or attached to a post or comment. For example, a post can include textual statements in combination with a JPEG image or animated image. A like or dislike can be submitted in response to a particular post or comment. Examples of uploaded files include presentations, documents, multimedia files, and the like. Users can follow a record by subscribing to the record, as mentioned above. Users can also follow other entities such as other types of data objects, other users, and groups of users. Feed tracked updates regarding such entities are one type of update that can be received and included in the user's news feed. Any number of users can follow a particular entity and thus view updates pertaining to that entity on the users' respective news feeds. In some social networks, users may follow each other by establishing connections with each other, sometimes referred to as “friending” one another. By establishing such a connection, one user may be able to see information generated by, generated about, or otherwise associated with another user. For instance, a first user may be able to see information posted by a second user to the second user's personal social network page. One implementation of such a personal social network page is a user's profile page, for example, in the form of a web page representing the user's profile. In one example, when the first user is following the second user, the first user's news feed can receive a post from the second user submitted to the second user's profile feed. A user's profile feed is also referred to herein as the user's “wall,” which is one example of a social network feed displayed on the user's profile page. In some implementations, a social network feed may be specific to a group of users of a social networking system. For instance, a group of users may publish a news feed. Members of the group may view and post to this group feed in accordance with a permissions configuration for the feed and the group. Updates in a group context can also include changes to group status information. In some implementations, when data such as posts or comments input from one or more users are submitted to a social network feed for a particular user, group, object, or other construct within a social networking system, an email notification or other type of network communication may be transmitted to all users following the user, group, or object in addition to the inclusion of the data as a feed item in one or more feeds, such as a user's profile feed, a news feed, or a record feed. In some social networking systems, the occurrence of such a notification is limited to the first instance of a published input, which may form part of a larger conversation. For instance, a notification may be transmitted for an initial post, but not for comments on the post. In some other implementations, a separate notification is transmitted for each such update. The term “multi-tenant database system” generally refers to those systems in which various elements of hardware and/or software of a database system may be shared by one or more customers. For example, a given application server may simultaneously process requests for a great number of customers, and a given database table may store rows of data such as feed items for a potentially much greater number of customers. An example of a “user profile” or “user's profile” is a database object or set of objects configured to store and maintain data about a given user of a social networking system and/or database system. The data can include general information, such as name, title, phone number, a photo, a biographical summary, and a status, e.g., text describing what the user is currently doing. As mentioned below, the data can include social media messages created by other users. Where there are multiple tenants, a user is typically associated with a particular tenant. For example, a user could be a salesperson of a company, which is a tenant of the database system that provides a database service. The term “record” generally refers to a data entity having fields with values and stored in database system. An example of a record is an instance of a data object created by a user of the database service, for example, in the form of a CRM record about a particular (actual or potential) business relationship or project. The record can have a data structure defined by the database service (a standard object) or defined by a user (custom object). For example, a record can be for a business partner or potential business partner (e.g., a client, vendor, distributor, etc.) of the user, and can include information describing an entire company, subsidiaries, or contacts at the company. As another example, a record can be a project that the user is working on, such as an opportunity (e.g., a possible sale) with an existing partner, or a project that the user is trying to get. In one implementation of a multi-tenant database system, each record for the tenants has a unique identifier stored in a common table. A record has data fields that are defined by the structure of the object (e.g., fields of certain data types and purposes). A record can also have custom fields defined by a user. A field can be another record or include links thereto, thereby providing a parent-child relationship between the records. The terms “social network feed” and “feed” are used interchangeably herein and generally refer to a combination (e.g., a list) of feed items or entries with various types of information and data. Such feed items can be stored and maintained in one or more database tables, e.g., as rows in the table(s), that can be accessed to retrieve relevant information to be presented as part of a displayed feed. The term “feed item” (or feed element) generally refers to an item of information, which can be presented in the feed such as a post submitted by a user. Feed items of information about a user can be presented in a user's profile feed of the database, while feed items of information about a record can be presented in a record feed in the database, by way of example. A profile feed and a record feed are examples of different types of social network feeds. A second user following a first user and a record can receive the feed items associated with the first user and the record for display in the second user's news feed, which is another type of social network feed. In some implementations, the feed items from any number of followed users and records can be combined into a single social network feed of a particular user. As examples, a feed item can be a social media message, such as a user-generated post of text data, and a feed tracked update to a record or profile, such as a change to a field of the record. Feed tracked updates are described in greater detail below. A feed can be a combination of social media messages and feed tracked updates. Social media messages include text created by a user, and may include other data as well. Examples of social media messages include posts, user status updates, and comments. Social media messages can be created for a user's profile or for a record. Posts can be created by various users, potentially any user, although some restrictions can be applied. As an example, posts can be made to a wall section of a user's profile page (which can include a number of recent posts) or a section of a record that includes multiple posts. The posts can be organized in chronological order when displayed in a GUI, for instance, on the user's profile page, as part of the user's profile feed. In contrast to a post, a user status update changes a status of a user and can be made by that user or an administrator. A record can also have a status, the update of which can be provided by an owner of the record or other users having suitable write access permissions to the record. The owner can be a single user, multiple users, or a group. In some implementations, a comment can be made on any feed item. In some implementations, comments are organized as a list explicitly tied to a particular feed tracked update, post, or status update. In some implementations, comments may not be listed in the first layer (in a hierarchal sense) of feed items, but listed as a second layer branching from a particular first layer feed item. A “feed tracked update,” also referred to herein as a “feed update,” is one type of update and generally refers to data representing an event. A feed tracked update can include text generated by the database system in response to the event, to be provided as one or more feed items for possible inclusion in one or more feeds. In one implementation, the data can initially be stored, and then the database system can later use the data to create text for describing the event. Both the data and/or the text can be a feed tracked update, as used herein. In various implementations, an event can be an update of a record and/or can be triggered by a specific action by a user. Which actions trigger an event can be configurable. Which events have feed tracked updates created and which feed updates are sent to which users can also be configurable. Social media messages and other types of feed updates can be stored as a field or child object of the record. For example, the feed can be stored as a child object of the record. A “group” is generally a collection of users. In some implementations, the group may be defined as users with a same or similar attribute, or by membership. In some implementations, a “group feed”, also referred to herein as a “group news feed”, includes one or more feed items about any user in the group. In some implementations, the group feed also includes updates and other feed items that are about the group as a whole, the group's purpose, the group's description, and group records and other objects stored in association with the group. Threads of updates including group record updates and social media messages, such as posts, comments, likes, etc., can define group conversations and change over time. An “entity feed” or “record feed” generally refers to a feed of feed items about a particular record in the database. Such feed items can include feed tracked updates about changes to the record and posts made by users about the record. An entity feed can be composed of any type of feed item. Such a feed can be displayed on a page such as a web page associated with the record, e.g., a home page of the record. As used herein, a “profile feed” or “user's profile feed” generally refers to a feed of feed items about a particular user. In one example, the feed items for a profile feed include posts and comments that other users make about or send to the particular user, and status updates made by the particular user. Such a profile feed can be displayed on a page associated with the particular user. In another example, feed items in a profile feed could include posts made by the particular user and feed tracked updates initiated based on actions of the particular user. FIG. 1 shows a system diagram of an example of a database system 100 for providing notifications of users concurrently interacting with the same feed item of a social network feed, in accordance with some implementations. Database system 100 may provide communications to be transmitted among a variety of different hardware and/or software components. In FIG. 1, database system 100 includes a social network feed server 102, a user system 104a and a user system 104b, an enterprise database 106, and a social network database 108. Social network feed server 102, or “feed server” 102, may communicate with all other components of database system 100. This communication may be facilitated through a combination of networks and interfaces. Feed server 102 can include one or many servers, and in alternative implementations can include some or all of enterprise database 106 and social network database 108. Also or alternatively, data stored in enterprise database 106 and social network database 108 can be arranged in tables on a shared database. Feed server 102 may act as a communication intermediary between user systems 104a and 104b and enterprise database 106 and social network database 108. For example, data sent to feed server 102 from user system 104a may be processed by feed server 102 and sent to one or both of enterprise database 106 and social network database 108. In addition, the data sent to feed server 102 can include data identifying the user, a feed item with which the user is interacting, and a type of interaction the user is having with the feed item. Using such feed interaction identification data from various user systems, feed server 102 can determine if two or more user systems are concurrently interacting with the same feed item. A user system 104a or 104b may be any type of computing device which can communicate via one or more data networks with a server, and can display a social network feed in a user interface. For example, user systems 104a and 104b may be portable electronic devices such as smartphones, tablets, laptops, wearable devices such as Google Glass®, other optical head-mounted display (OHMD) devices, smart watches, etc. In some instances, user systems 104a and 104b may be another server or a desktop computer operated by a user. Additionally, user systems 104a and 104b may be different types of computing devices. For example, user system 104a may be a desktop computer whereas user system 104b may be a smartphone. Enterprise database 106 can be part of a multitenant database system and can be configured to transmit data to and from feed server 102. In some implementations, user system 104a can access enterprise database 106 through a request made by feed server 102. Also or alternatively, feed server 102 can access enterprise database 106 without a request from user system 104a. Enterprise database 106 can store and maintain database records of an organization in an enterprise system such as CRM records in the form of accounts, opportunities, leads, cases, contacts, contracts, campaigns, solutions, quotes, purchase orders, etc. The records can be hierarchically arranged in enterprise database 106 with some data objects identifying relationships between the records. In addition, enterprise database 106 can receive requests from feed server 102 including, but not limited to a query, a request to create a new record, and or a request to modify an existing record. Enterprise database 106 and social network database 108 can reciprocally communicate with each other to create records or modify records on one or both databases. Social network database 108 can store user profiles, feed items, data objects identifying particular feeds, and various metadata. For example, updates occurring within an enterprise system can be stored as feed items with a dependency relationship to one or more social network feeds. Also, social network database 108 can store feed interaction identification data processed by feed server 102. The feed interaction identification data can include data indicating whether a user has been or is currently beginning to interact with a particular feed item and can include metadata associated with the interaction. FIG. 2 shows a flow chart of an example of a method 200 for notifying a user that another user is interacting with a feed item of a feed of a social networking system associated with a database system, in accordance with some implementations. Method 200 and other methods described herein may be implemented using the database system 100 of FIG. 1, although the implementations of such methods are not limited to database system 100. In block 204 of FIG. 2, feed interaction identification data as described above is received at feed server 102 of database system 100 from a first user system, such as user system 104a of FIG. 1. For example, a user can access a page displaying a feed. As feed items appear in a user interface presenting the feed on the first user system, feed interaction identification data indicating that the user is viewing a particular feed item and, thus, has begun interacting with the feed item, can be generated. Also or alternatively, feed interaction identification data can be generated to indicate that a user has taken an affirmative act to start interacting with a feed item. For example, a user may hover a mouse pointer over the feed item in the user interface, click a “like” selection, or start to type text in a comment area to respond to a feed item such as a post. A user system can send such feed interaction identification data to a server implementing part or all of the blocks of method 200 continuously or at specified intervals. The feed interaction identification data can include metadata to identify the specific actions taken by or initiated by a user to create, delete or modify data stored on a database such as enterprise database 106 or social network database 108 of FIG. 1. FIG. 4 shows an example of a user interface 400 with a feed item of a social network feed in the form of a GUI as displayed on a computing device, in accordance with some implementations. In this example, displayed feed items of the feed include a post 404 created by a user 436 and comments 408 and 412 submitted by other users in response to post 404. In some implementations, a feed item can encompass the post and the comments in response to the post. Comments 408 and 412 can be arranged hierarchically in relation to post 404 and stored in a database such as social network database 108 of FIG. 1. In some implementations, database tables can be maintained to include feed item IDs identifying particular feed items with which a user is interacting and user IDs of users who are interacting with a given feed item. FIG. 6 shows an example of a user interface 600 with a social network feed with notifications in the form of a GUI as displayed on a computing device, in accordance with some implementations. User interface 600 includes social network feed 604 and feed items 608a, 608b, 608c, and 608d. In this example, a user has begun interacting with feed item 608d by clicking in a “Write a Comment” box displayed in conjunction with feed item 608d. Feed interaction identification data can be generated to identify this interaction including a timestamp of when a user first started interacting with feed item 608d by clicking on or in feed item 608d, any user input such as text entered in a comment box, a user ID of the user interacting with item 608d, and a feed item ID uniquely identifying feed item 608d in a database system. Returning to FIG. 2, in block 208, it is determined that the first user is interacting with a feed item. In some implementations, the feed interaction identification data received in block 204 can be processed to identify the timestamp of when the user first started interacting with feed item 608d, any user input, the user ID, and the feed item ID. For example, returning to FIG. 1, feed server 102 may submit the received user ID and feed item ID as queries to a database or databases storing tables of user IDs and feed item IDs. In addition, the feed server can store the feed interaction identification data received in block 204 in a database with pointers or links to the particular user ID and/or feed item ID. Thus, a request by the feed server to the social network database could determine at any given whether and how many users are interacting with a feed item at a given time. Returning to FIG. 4, a user could initiate an interaction with post 404 or with comments 408 and 412 by hovering a mouse pointer over or clicking in a comment area 420. This initiation can cause the user's device to send feed interaction identification data as described above to a feed server. The user can also input text, delete text, or in any other way modify text in comment area 420 with keystrokes from a keyboard. In some implementations, each keystroke can be communicated as feed interaction identification data to indicate that the user has started interacting with the feed item and continuously update the feed server to inform the server that the user is still interacting with the feed item. In some other implementations, even though a user has selected the comment area, feed interaction identification data is not sent to the feed server until the user has started inputting text in the comment area. In some other implementations, interaction with a social network publisher 612 of FIG. 6 can cause feed interaction identification data to be communicated to a feed server. For example, a user hovering a mouse pointer over the “What are you working on?” field, clicking on an “attach” selection, a “link” selection or a “file” selection in publisher 612 can cause data identifying such an interaction to be immediately transmitted to a feed server to inform the server that a user is interacting with a feed item. Returning to FIG. 4, hovering a pointer over or clicking on a comment button 424, a like button 428, or a share file button 432 can also be communicated as feed interaction identification data to a feed server, where at block 208 of FIG. 2 the feed server determines that an interaction has commenced or is in progress. With comment button 424 of FIG. 4, a notification can then be generated and displayed to any users viewing the feed item of interest to indicate that the user has viewed the feed item and has begun commenting on the feed item. In some implementations, selection of a submit button 440 is communicated to the feed server to allow the server to determine that an interaction such as commenting has stopped. Returning to FIG. 2, in block 208, a determination that a user is interacting with a feed item can be done in near real time, in some implementations. For example, near real time determinations can be made with a line of communication that temporarily opens between the feed server and a user's device immediately upon the user interacting with a feed item as explained above. Selecting submit button 440 of FIG. 4, in some but not all implementations, can cause the connection to close. Alternatively, near real time determinations can be made by a persistent communication link between the feed server and a user's device. The persistent connection allows the feed server to constantly monitor the activity of the user and make determinations immediately in response to user actions. In some implementations, while a user moves his mouse pointer within his user interface, coordinates of the pointer can be derived by the user's device and/or the feed server. Based upon the derived coordinates, at block 208 of FIG. 2, a determination that the user is interacting with one or more feed items may be made. In another example, the feed server or user's device can determine that a user has had post 404 of FIG. 4 located in a central region of a user interface for at least a threshold amount of time, allowing a determination to be made that the user viewed and is thus interacting with post 404. Additionally, scrolling up or down in a page to change post 404 from being centrally located or moving a mouse pointer away from post 404 for some threshold amount of time can be communicated to the feed server to indicate that the user is no longer currently viewing and/or no longer interacting with the feed item. Also or alternatively, a user can select publisher 612 of FIG. 6 to input text to comment on a feed item, and mouse cursor coordinates previously gathered can be used to accurately determine which feed item is being commented on. In some implementations, the feed server can identify different types of interactions with a feed item. For example, the user may only view a feed item by having the feed item displayed in the user's user interface. Another type of interaction is when the user comments on a feed item. Alternatively, a user can complete a comment or cease creating the comment for a particular duration, indicating that the interaction has been completed. Accessing another page in which the feed item is not displayed can also be interpreted as completion of the interaction. In such cases, the type of interaction such as a view, comment, termination of user input, or loading of another page can be communicated as feed interaction identification data or included metadata to the feed server. Using the techniques described above, a feed server can process and update determined interactions with multiple feed items by various users. For example, in FIG. 6, a server can determine that the user has commented on feed item 608a, and the server can determine that the user has commented on feed item 608d. FIG. 5 shows an example of a user interface 500 with a social network feed with notifications in the form of a GUI as displayed on a computing device, in accordance with some implementations. A comment area 508 shows text input by a user in response to a post 504, as well as cursor 512 positioned at the end of the text in comment area 508. In some implementations, the number of characters or words entered in comment area 508 can be communicated as feed interaction identification data or as metadata of the feed interaction identification data. A feed server can compare this numerical data with a threshold to determine that a sufficient amount of user input has been received to conclude that a user is interacting with post 504. In this example, cursor 512 is a flashing or blinking text cursor in comment area 508. In some implementations, duration between user actions within a user interface can be communicated as feed interaction identification data or included metadata for a server to determine when a user is interacting with a feed item in block 208 of FIG. 2. For example, a duration of 5 seconds between a user selecting comment area 508 of FIG. 5 and beginning to type in comment area 508 could be communicated. Also or alternatively, a monitored duration can be reset depending on the type of user action, for example, the user navigating to another page from user interface 500. Returning to FIG. 2, in block 212, it is determined that a second user is concurrently interacting with the same feed item of block 208. For example, a server can maintain a list of users who are identified as concurrently interacting with the same feed item. The list can be in the form of a database table of user IDs stored in an appropriate database, where the list references a given feed item. The list is updated as user devices indicate to the server that a user is interacting with or is no longer interacting with the feed item. For example, when the second user has begun viewing, commenting, or otherwise interacting with the feed item, the second user's device can send a message to convey this status information to the server, where the message identifies the second user by user ID and identifies the feed item with which the second user interacting by a feed item ID. Also or alternatively, a server can be configured to ping, at sufficiently frequent intervals, devices of users who have accessed the social networking system for status information of which feed item a given user is interacting with. A server can thus appropriately add user IDs to a concurrent interaction list with respect to a given feed item for the purpose of determining which users are concurrently interacting with the same feed item. By the same token, in block 212, a user can be removed from a concurrent interaction list when data sent from the user's device to the server indicates that the user is no longer interacting with the associated feed item. For example, when a user clicks on, hovers a mouse pointer over, or begins commenting on a different feed item of the feed, the user can be removed from the list. In some implementations, a user submitting a response to a feed item associated with a concurrent interaction list, such as the user liking a post or submitting a comment on a post by clicking a “share” or “publish” button in a user interface, can cause that user to be removed from the concurrent interaction list. That is, the clicking of “share” by a user can be communicated to a server, and the server can process the action to determine that the first user is no longer interacting with the feed item. In some implementations, multiple user interactions can be processed as factors to determine whether a user is no longer interacting with a feed item. For example, the system can be configured to remove a user from a concurrent interaction list after the user has both shared a comment on the post and hovered a mouse pointer over a different post. In some implementations, the system is configured to account for user idle time when maintaining a concurrent interaction list or otherwise monitoring user activity to determine whether users are concurrently interacting with the same feed item. For example, a system administrator can set a time threshold of 5 minutes of idle time. A first user begins to interact with a feed item, for instance, by beginning to type a comment in a comment box, but does not share the comment and enters no further user input for 6 minutes. Only after the 5-minute threshold is exceeded, this condition is communicated to the server, causing the server to then determine that the first user is no longer interacting with the feed item and thus remove the user from the concurrent interaction list. The time threshold can be configurable by a system administrator to be on the order of seconds, minutes, hours, etc. as desired for a particular implementation. In some implementations, independent of any idle time monitoring as described above, an interaction by a second user can be determined to be “concurrent” with that of a first user when the interactions occur within a designated timeframe. For instance, a time threshold of 5 minutes is specified. If a first user begins interacting with a feed item, and a second user begins interacting with the same feed item less than 5 minutes after the first user began interacting with the feed item, an appropriate notification is displayed to inform one or both users that they are interacting with the same feed item. A server can receive and compare timestamps of users' interactions for this purpose. For example, if one user begins interacting with a feed item at 10:01 am, and another user begins interacting with the same feed item at 10:02 am, then a server could determine that these interactions fall within the 5-minute time threshold and are thus sufficiently “concurrent” to cause appropriate notifications to be generated and displayed. It should be appreciated that some implementations of the disclosed systems are capable of monitoring many users interacting with the same feed item at the same time and communicating appropriate notifications. As each additional user starts interacting with the same feed item, essentially the same determination of block 212 is made in near real time. Some or all of the techniques described above for determining that the first user is interacting with a feed item block 208 can be practiced to implement block 212. In such cases, and as discussed in further detail below, where more than one user is interacting with the same feed item, a notification in a user interface can indicate that another user is concurrently interacting with the same feed item. In block 216, a notification is sent to users concurrently interacting with the same feed item. Such a notification can be generated and displayed in a user interface on devices of the appropriate users. For example, FIG. 4 shows a notification in the form of a pop-up window 442 displayed adjacent to and graphically linked with post 404. The pop-up window 442 informs a user viewing user interface 400 that other users are concurrently interacting with post 404. Post metadata 444 included in pop-up window 442 indicates the number of users viewing post 404, and post metadata 448 indicates that another user is in the process of preparing a comment on post 404. In some implementations, metadata in the notification can be formatted with rich text and can include hyperlinks to other documents or pages, so a user can quickly click through the metadata to access details represented by the metadata. For example, a hyperlink to a user's profile of a user who is interacting with a given feed item may be clicked by another user to learn more about the user who is commenting on a post. In some implementations, a notification such as pop-up window 442 or a similar pop-up window 616 in FIG. 6 can be refreshed in near real time to indicate whether a concurrent interaction is still occurring, how users are interacting, and past interactions with a given feed item. For example, a notification 516 of FIG. 5 can be initially displayed to indicate, “10 People are viewing Tom Smith's post.” After some amount of time, refreshed notification 520 can be displayed to indicate, “Peda Pola is commenting on Tom Smith's post.” In some implementations, both notifications 516 and 520 may be displayed to separately inform how many other users are viewing a feed item and how many/which users are commenting on a feed item. In some other implementations, only notification 516 or 520 is displayed at a given time. In other implementations, notifications 516 and 520 can be displayed as new feed items in a feed. Also or alternatively, a notification as described above can cause an instant messaging system to be activated or accessed, so instant messages can be sent between users interacting with the same feed item. In this way, for example, one user could quickly connect with another user and discuss who is going to respond to a given post to avoid redundancy and save time. In some
{'application_number': '<application-reference appl-type="utility">\n<document-id>\n<country>US</country>\n<doc-number>14645248</doc-number>\n<date>20150311</date>\n</document-id>\n</application-reference>', 'publication_number': '<publication-reference>\n<document-id>\n<country>US</country>\n<doc-number>20160269328</doc-number>\n<kind>A1</kind>\n<date>20160915</date>\n</document-id>\n</publication-reference>', 'source_file': './application/2016/ipa160915.xml', 'source_data': 'USPTO-Application'}