docs: def _from_dict(cls, _dict):
          """Initialize a Grammars object from a json dictionary."""
          args = {}
          if 'grammars' in _dict:
              args['grammars'] = [
                  Grammar._from_dict(x) for x in (_dict.get('grammars'))
              ]
          else:
              raise ValueError(
                  'Required property \'grammars\' not present in Grammars JSON')
          return cls(**args)