code: def normalize_body(self, b):
          
          if b is None: return ''
  
          if self.is_json():
              # TODO ???
              # I don't like this, if we have a content type but it isn't one
              # of the supported ones we were returning the exception, which threw
              # Jarid off, but now it just returns a string, which is not best either
              # my thought is we could have a body_type_subtype method that would 
              # make it possible to easily handle custom types
              # eg, "application/json" would become: self.body_application_json(b, is_error)
              b = json.dumps(b, cls=ResponseBody)
  
          else:
              # just return a string representation of body if no content type
              b = String(b, self.encoding)
  
          return b
docs: return the body as a string, formatted to the appropriate content type
  
          :param b: mixed, the current raw body
          :returns: unicode string