gistfile1.js

function Foo() {
  this.destructors = [];
}

Foo.prototype.bind = function(ele, type, handler) {
  ele.addEventListener(type, handler);
  this.destructors.push(function() {
    ele.removeEventListener(type, handler);
  });
}

Foo.prototype.teardown = function() {
  this.destructors.forEach(function(fn) { fn(); });
}