function test() {

// RegExp -> Get -> [[Get]]
var get = [];
var re = { constructor: null };
re[Symbol.match] = true;
var p = new Proxy(re, { get: function(o, k) { get.push(k); return o[k]; }});
RegExp(p);
return get[0] === Symbol.match && get.slice(1) + '' === "constructor,source,flags";
      
}

if (!test())
    throw new Error("Test failed");