code: def validate(self, data, many=None, partial=None):
          
          try:
              self._do_load(data, many, partial=partial, postprocess=False)
          except ValidationError as exc:
              return exc.messages
          return {}
docs: Validate `data` against the schema, returning a dictionary of
          validation errors.
  
          :param dict data: The data to validate.
          :param bool many: Whether to validate `data` as a collection. If `None`, the
              value for `self.many` is used.
          :param bool|tuple partial: Whether to ignore missing fields and not require
              any fields declared. Propagates down to ``Nested`` fields as well. If
              its value is an iterable, only missing fields listed in that iterable
              will be ignored. Use dot delimiters to specify nested fields.
          :return: A dictionary of validation errors.
          :rtype: dict
  
          .. versionadded:: 1.1.0