anchor.diff:  In the NGSI data model, attributes have an *attribute name*,
   an *attribute type*, an *attribute value* and *metadata*. 
    * The attribute name describes which kind of property of the entity the attribute value represents, for example *current_speed*.
  - * The attribute type represents the NGSI value type of the attribute value. Note that FIWARE NGSI has its own type system for attribute values, so NGSI value types are not the same as JSON types.
  + * The attribute type represents the NGSI value type of the attribute value.
  + Note that FIWARE NGSI has its own type system for attribute values, so NGSI value types are not the same as JSON types.
    * The attribute value finally contains
     * the actual data
     * optional **metadata** describing properties of the attribute value like e.g. accuracy, provider, or a timestamp
  
positive.code: * Successful operation uses 204 No Content
  * Errors use a non-200 and (optionally) an error payload. See subsection on Error Responses for more details.
  
  
  + Parameters
      + entityId: Bcn_Welt (required, string) - Entity ID
  
  + Request (application/json)
  
  
negative.code: FORMAT: 1A
  HOST: http://orion.lab.fiware.org
  TITLE: FIWARE-NGSI v2 Specification
  DATE: 30 September 2015
  VERSION: 2.0-wip1
  PREVIOUS_VERSION: <placeholder>
  APIARY_PROJECT: fiware-ngsi-v2
  SPEC_URL: https://telefonicaid.github.io/fiware-orion/api/v2/
  GITHUB_SOURCE: http://github.com/telefonicaid/fiware-orion.git
  
  # FIWARE-NGSI v2 Specification
  
  This specification defines the FIWARE-NGSI version 2 API. FIWARE-NGSI v2 is intended to manage all the whole lifecycle of
  context information including updates, queries, registrations and subscriptions.
  
  ## Editors
  
    + José Manuel Cantera Fonseca, Telefónica I+D
    + Fermín Galán, Telefónica I+D. 
    + Tobias Jacobs, NEC
    
  ## Acknowledgements
  
  The editors would like to express their gratitude to the following people who actively contributed to this specification:
  Juan José Hierro, Marcos Reyes, Ken Gunnar, Antonio López, ... 
    
  ## Status
  
  This is a work in progress and is changing on a daily basis.
  Please send your comments to fiware-ngsi@lists.fiware.org. You can
  