anchor.diff:  ### Get attribute data [GET /v2/entities/{entityId}/attrs/{attrName}{?type}]
   
   Returns a JSON object with the attribute data of the attribute. The object follows the JSON
  -representation for attributes (described in "JSON Entity Representation" section).
  +representation for attributes (described in "JSON Attribute Representation" section).
   
   Response:
   
  
positive.code:     + geometry: point (optional, string) - Geografical area to which the query is restricted.
        See [Geographical Queries](#geographical_queries).
      
      + coords: 40.6391,-8.6533 (optional, string) - List of latitude-longitude pairs of coordinates
        separated by ';'.
        See [Geographical Queries](#geographical_queries).
      
      + limit: 20 (optional, number) - Limits the number of entities to be retrieved
      
  
negative.code:   than those, an error is raised. See detail in "Notification Messages" section.
  + `timesSent` (not editable, only present in GET operations): Number of notifications sent due to
     this subscription.
  + `lastNotification` (not editable, only present in GET operations): Last notification date in ISO8601 format.
  
  An `http` object contains the following subfields:
  
  