Implement late static binding

Implement static keyword

Sample code :

<?php
class foo {
  public static $foo = 'from FOO';
  function bar() {
    echo static::$foo;
  }
}

class bar {
  public static $foo = 'from Bar';
}

$barInstance = new bar();
$barInstance->bar();

This should result in a from BAR output. Don't know what is the JS equivalent.