private bool IsEntity(IGraphType type)
        {
            if (type.IsInputObjectType())
            {
                return(false);
            }

            var directive = type.GetExtensionDirectives <ASTNode>().Directive("key");

            if (directive != null)
            {
                return(true);
            }

            var ast = type.GetAstType <IHasDirectivesNode>();

            if (ast == null)
            {
                return(false);
            }

            var keyDir = ast.Directives.Directive("key");

            return(keyDir != null);
        }