code: def decode_map(self, data_type, obj):
          
          if not isinstance(obj, dict):
              raise bv.ValidationError(
                  'expected dict, got %s' % bv.generic_type_name(obj))
          return {
              self.json_compat_obj_decode_helper(data_type.key_validator, key):
              self.json_compat_obj_decode_helper(data_type.value_validator, value)
              for key, value in obj.items()
          }
docs: The data_type argument must be a Map.
          See json_compat_obj_decode() for argument descriptions.