code: def json(cls, status_code, process):
          
          def func(response):
              ret = None
              if cls.boolean(status_code)(response):
                  ret = response.json() or {}
              return process(ret)
          return func
docs: Callback to validate and extract a JSON object.
  
          The returned callback checks a given response for the given
          status_code using :function:`response_boolean`. On success the
          response JSON is parsed and returned.
  
          Args:
  
              status_code(int): The http status code to consider a success
  
          Returns:
  
              A function that given a response returns the JSON object
                  in the given response. Raises a :class:`HeliumError` if
                  the response code does not match.