private static CallNodeVisitor ParseScript(string script)
        {
            JSParser parser = new JSParser();
            var      p      = parser.Parse(script);

            CallNodeVisitor visitor = new CallNodeVisitor();

            p.Accept(visitor);
            return(visitor);
        }
        private static HashSet <string> GetCalledFunctionNames(string script)
        {
            CallNodeVisitor visitor = ParseScript(script);

            return(visitor.CalledFunctions);
        }