code: def replace(self, parameters=_void, return_annotation=_void):
          
  
          if parameters is _void:
              parameters = self.parameters.values()
  
          if return_annotation is _void:
              return_annotation = self._return_annotation
  
          return type(self)(parameters, return_annotation=return_annotation)
docs: Creates a customized copy of the Signature.
          Pass 'parameters' and/or 'return_annotation' arguments
          to override them in the new copy.