code: def representation(self, mediatype):
          
          def wrapper(func):
              self.representations[mediatype] = func
              return func
          return wrapper
docs: Allows additional representation transformers to be declared for the
          api. Transformers are functions that must be decorated with this
          method, passing the mediatype the transformer represents. Three
          arguments are passed to the transformer:
  
          * The data to be represented in the response body
          * The http status code
          * A dictionary of headers
  
          The transformer should convert the data appropriately for the mediatype
          and return a Flask response object.
  
          Ex::
  
              @api.representation('application/xml')
              def xml(data, code, headers):
                  resp = make_response(convert_data_to_xml(data), code)
                  resp.headers.extend(headers)
                  return resp