code: def from_mapping(self, mapping: Optional[Mapping[str, Any]]=None, **kwargs: Any) -> None:
          
          mappings: Dict[str, Any] = {}
          if mapping is not None:
              mappings.update(mapping)
          mappings.update(kwargs)
          for key, value in mappings.items():
              if key.isupper():
                  self[key] = value
docs: Load the configuration values from a mapping.
  
          This allows either a mapping to be directly passed or as
          keyword arguments, for example,
  
          .. code-block:: python
  
              config = {'FOO': 'bar'}
              app.config.from_mapping(config)
              app.config.form_mapping(FOO='bar')
  
          Arguments:
              mapping: Optionally a mapping object.
              kwargs: Optionally a collection of keyword arguments to
                  form a mapping.