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