code: def _validate_schema(self, schema, field, value):
          
          if schema is None:
              return
  
          if isinstance(value, Sequence) and not isinstance(value, _str_type):
              self.__validate_schema_sequence(field, schema, value)
          elif isinstance(value, Mapping):
              self.__validate_schema_mapping(field, schema, value)
docs: {'type': ['dict', 'string'],
               'anyof': [{'validator': 'schema'},
                         {'validator': 'bulk_schema'}]}