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