code: def _is_valid_close_code(self, code):
          
          if code < 1000:
              return False
          if 1004 <= code <= 1006:
              return False
          if 1012 <= code <= 1016:
              return False
          if code == 1100:
              # not sure about this one but the autobahn fuzzer requires it.
              return False
          if 2000 <= code <= 2999:
              return False
          return True
docs: :returns: Whether the returned close code is a valid hybi return code.