public static function typeNameMetaFieldDef() { if (!isset(self::$map['__typename'])) { self::$map['__typename'] = FieldDefinition::create(['name' => '__typename', 'type' => Type::nonNull(Type::string()), 'description' => 'The name of the current Object type at runtime.', 'args' => [], 'resolve' => function ($source, $args, $context, ResolveInfo $info) { return $info->parentType->name; }]); } return self::$map['__typename']; }