Proxy in nodejs

Proxy.js

let validator = {
    set: function name(Obj, param, value) {
        if(param === 'age'){
            if(! Number.isInteger(value)) throw new Error("age is not an number type")

            if( !(value > 18 && value < 80)){
               throw Error("age range error, age must between 18 to 80 ");
            } 
        }

        return true;        
    }
}

var person = new Proxy({}, validator);


person.age = 23;