anchor.diff:              "error": "NotFound",
               "description": "The entity does not have such an attribute"
           }
  -
  -
  -### Update an attribute [PUT /v2/entities/{entityId}/attrs/{attrName}]
  -
  -+ Parameters
  -    + entityId: Bcn_Welt (required, string) - Entity ID
  -    + attrName: temperature (required, string) - Attribute Name
  +        
  +
  +### Update [PUT /v2/entities/{entityId}/attrs/{attrName}]
  +
  ++ Parameters
  +    + entityId: Bcn_Welt (required, string) - Entity ID
  +    + attrName: temperature (required, string) - Attribute name.
   
   + Request (application/json)
   
           {
               "value": 25.0,
  -            "unitCode": "CEL"
  +            "metadata": {
  +               "unitCode": "CEL"
  +            }
           }
   
   + Response 200
   
   
  -### Update an attribute value [PUT /v2/entities/{entityId}/attrs/{attrName}/value]
  -
  -+ Parameters
  -    + entityId: Bcn_Welt (required, string) - Entity ID
  -    + attrName: temperature (required, string) - Attribute Name
  +### Remove [DELETE /v2/entities/{entityId}/attrs/{attrName}]
  +
  ++ Parameters
  +    + entityId: Bcn_Welt (required, string) - Entity ID
  +    + attrName: temperature (required, string) - Attribute name.
  +
  ++ Response 204
  +        
  +
  +## Attribute Value [/v2/entities/{entityId}/attrs/{attrName}/value]
  +
  +### Get. As text [GET /v2/entities/{entityId}/attrs/{attrName}/value]
  +
  ++ Parameters
  +    + entityId: Bcn_Welt (required, string) - Entity ID
  +    + attrName: temperature (required, string) - Attribute name.
  +    
  ++ Request
  +
  +  + Headers
  +
  +      Accept: text/plain
  +
  ++ Response 200 (text/plain)
  +
  +        300
  +
  +
  +### Get. As JSON [GET /v2/entities/{entityId}/attrs/{attrName}/value]
  +
  ++ Parameters
  +    + entityId: Bcn_Welt (required, string) - Entity ID
  +    + attrName: temperature (required, string) - Attribute name.
  +
  ++ Response 200 (application/json)
  +
  +        {
  +            "value": 300
  +        }
  +
  +
  +### Update. As Text [PUT /v2/entities/{entityId}/attrs/{attrName}/value]
  +
  ++ Parameters
  +    + entityId: Bcn_Welt (required, string) - Entity ID
  +    + attrName: temperature (required, string) - Attribute name.
  +
  ++ Request (text/plain)
  +
  +        25.0
  +
  ++ Response 200
  +
  +
  +### Update. As JSON [PUT /v2/entities/{entityId}/attrs/{attrName}/value]
  +
  ++ Parameters
  +    + entityId: Bcn_Welt (required, string) - Entity ID
  +    + attrName: temperature (required, string) - Attribute name.
   
   + Request (application/json)
   
  
positive.code:         }
  
  + Response 200
  
  
  ### Remove an attribute [DELETE /v2/entities/{entityId}/attrs/{attrName}]
  
  + Parameters
      + entityId: Bcn_Welt (required, string) - Entity ID
      + attrName: temperature (required, string) - Attribute Name
  
  + Response 204
  
  
  # Group Subscriptions
  
negative.code: 
  # Group Context Attributes
  
  ## Attribute Collection [/v2/entities/{entityId}/attrs{?options}]
  
  ### List all. Normalized Mode. [GET /v2/entities/{entityId}/attrs]
  
  + Parameters
      + entityId: Bcn_Welt (required, string) - Entity ID
  
  + Response 200 (application/json)
  
          {
              "temperature": {
                 "type":     "number",
                 "value":    22.5,
                 "metadata": {
                   "unitCode": {
                      "type": "none",
                      "value": "CEL"
                   }
                 }
              },
              "humidity": {
                 "type": "number",
                 "value": 60,
                 "metadata": { }
              },
              "location": {
                "type": "geo:point",
                "value": "41.3763726, 2.1864475",
                "metadata": { }
              }
          }
  
  
  ### List all. keyValues Mode. [GET /v2/entities/{entityId}/attrs{?options}]
  
  + Parameters
      + entityId: Bcn_Welt (required, string) - Entity ID
      + options: keyValues (optional, string) - flags that payload is in `keyValues`mode.
  
  + Response 200 (application/json)
  
          {
              "temperature": 21.7,
              "humidity":    60,
              "location":    "41.3763726, 2.1864475"
          }
  
          
  ### Replace all. keyValues mode [PUT /v2/entities/{entityId}/attrs{?options}]
  
  + Parameters
      + entityId: Bcn_Welt (required, string) - Entity ID
      + options: keyValues (optional, string) - flags that payload is in `keyValues`mode.
  
  + Request (application/json)
  
          {
              "temperature": 21.7,
              "seatsNumber": 12
          }
  
  + Response 200
          
  
  ## Single Attribute [/v2/entities/{entityId}/attrs/{attrName}]
  
  ### Get [GET /v2/entities/{entityId}/attrs/{attrName}]
  
  + Parameters
      + entityId: Bcn_Welt (required, string) - Entity ID
      + attrName: illuminance (required, string) - Attribute name.
  
  + Response 200 (application/json)
  
          {
              "value": 300,
              "type": "number",
              "metadata": {
                "accuracy": {
                  "value": 1.0,
                  "type": "number"
                },
                "unitCode": {
                  "value": "LX",
                  "type":  "none"
                }
              }
          }
  
  
  ### Get. Not exists [GET /v2/entities/{entityId}/attrs/{attrName}]
  
  + Parameters
      + entityId: Bcn_Welt (required, string) - Entity ID
      + attrName: mistake (required, string) - Attribute name.
  
  + Response 404 (application/json)
  
  