anchor.diff:  
   ### Retrieve entity [GET /v2/entities/{entityId}{?attrs}]
   
  -<table style="width: 100%; margin: 12px 0 0 0;">
  -<tr><td colspan="2"><strong>Required Parameters</strong></td></tr>
  -<tr><td colspan="2">none</td></tr>
  -<tr><td colspan="2"><strong>Optional Parameters</strong></td></tr>
  -<tr>
  -  <td style="padding-right: 40px; width: 140px;">attrs</td>
  -  <td>Comma-separated list of attribute names which data will be included in the response. If this parameter is not
  -  included, all the attributes are retrieved.</td>
  -</tr>
  -</table>
  -
   The response is an object representing the entity identified by the ID. The object follows
   the JSON entity representation format (described in a section above).
   
  
positive.code: * Errors use a non-200 and (optionally) an error payload. See subsection on Error Responses for more details.
  
  + Parameters
      + limit: 20 (optional, number)
      + offset: 20 (optional, number)
      + type: Room (optional, string)
      + id: Bcn_Welt (optional, string)
      + idPattern: (optional, string)
  
  + Response 200 (application/json)
  
  
negative.code: an opaque way. Nonetheless, the types described below are used to convey an special meaning
  
  * `date`:  identifies dates, in ISO8601 format. These attributes can be used with the
    greater than, lesser than, greater or equal, lesser or equal and range query operators. For instance
    (only the referred entity attribute is shown) :
  
  ```
  {
    "timestamp": {
      "value": "2017-06-17T07:21:24.238Z",
      "type: "date"
    }
  }
  ```
  
  * `geo:point`: identifies the location of the entity in geo-location queries. If an entity have several attributes
    of this type all them define a possible location for the entity from a geo-location query point of view. (TBD:
    check feasibility). An example can be found below (only the referred entity attribute is shown). 
  
  ```
  {
    "location": {
      "value": "41.3763726, 2.1864475,14",
      "type": "geo:point"
    }
  }
  ```
  
  ### Canonical format description
  