In python, you can call static/class methods from an instance, for example in the following:

class User:
    # class/static
    NUM_USERS = 0
    MAX_USERS = 10
    @classmethod
    def users_left(cls):
        print ('%d users left' % (cls.MAX_USERS - cls.NUM_USERS))
    # instance
    def __init__(self, name):
        self.name = name
        User.NUM_USERS += 1
    def greet(self):
        print ('Hello %s' % self.name)

u1 = User('Bob')
u2 = User('Todd')
u2.greet()
u2.users_left() # users_left() is a classmethod

However, in javascript it seems you must explicitly call the class, for example:

class User {
    static NUM_USERS = 0;
    static MAX_USERS = 10;
    static users_left() {
        console.log(User.MAX_USERS - User.NUM_USERS);
    }
    constructor(name) {
        this.name = name;
        User.NUM_USERS ++;
    }
    greet() {
        console.log('Hello', this.name);
    }
}

u1 = new User('Bob');
u2 = new User('Todd');
u2.greet();

u2.constructor.users_left(); // ok
User.users_left(); // ok
u2.users_left(); // error

Is there a way to 'fallback' in javascript like you can in python, or you must explicitly invoke the class?