I'm researching prototypes in JS.

1. Please tell me how to add the Map.isMap(object) function to the Map prototype.

I was able to make object.isMap() by code:

Map.prototype.isMap = function() {
  return this.__proto__.toString().toLowerCase().includes("map");
}

2. I know editing prototype chain is a bad practice in JS. What is the best way to create such function?