Map.prototype[Symbol.toStringTag]
New in JS2015.
Map.prototype [ Symbol.toStringTag ]- Value is the string
"Map".
[see Determine Type of Object]
console.log( Map.prototype [ Symbol.toStringTag ] === "Map" ); // true
New in JS2015.
Map.prototype [ Symbol.toStringTag ]"Map".[see Determine Type of Object]
console.log( Map.prototype [ Symbol.toStringTag ] === "Map" ); // true