code: def get_field_type_from_schema(schema_type, field_name):
      
      if field_name == '@class':
          return GraphQLString
      else:
          if field_name not in schema_type.fields:
              raise AssertionError(u'Field {} passed validation but was not present on type '
                                   u'{}'.format(field_name, schema_type))
  
          # Validation guarantees that the field must exist in the schema.
          return schema_type.fields[field_name].type
docs: Return the type of the field in the given type, accounting for field name normalization.