public static List <InvocationExpression> invocations(this MethodDeclaration methodDeclaration)
        {
            var astVisitors = new AstVisitors();

            methodDeclaration.AcceptVisitor(astVisitors, null);
            return(astVisitors.invocationExpressions);
        }
        public static List <LocalVariableDeclaration> variables(this MethodDeclaration methodDeclaration)
        {
            var astVisitors = new AstVisitors();

            methodDeclaration.AcceptVisitor(astVisitors, null);
            return(astVisitors.localVariableDeclarations);
        }