title: How to unbind document keypress event with anonymous function
body: <p>This is page's code.
  I can't modify this.</p>
  
  <pre><code>var Example = {};
  
  Example.create = function() {
      var obj = new Example.object();
      return obj;
  }
  
  Example.object = function(){
      this.initialize = initialize;
      function initialize() {
          window.addEventListener('load', activate);
      }
      function activate() {
          document.addEventListener('keypress', keyPressed);
      }
      function keyPressed(e) {
          alert("Hello!");
      }
  };
  
  Example.defaultObject = Example.create();
  Example.defaultObject.initialize();
  </code></pre>
  
  <p>I have tried many things...</p>
  
  <pre><code>document.onkeypress = null;
  document.keypress = null;
  document.removeEventListener('keypress');
  $(document).unbind('keypress');
  $(document).off("keypress");
  $("*").unbind('keypress');
  $(document).bind('keypress', function(e) { e.stopPropagation(); });
  </code></pre>
  
  <p>but all failed.</p>
  
  <p>How can I unbind event of document keypress?</p>