text: var obj = { num: 4 };
  var functionName = function (arg1, arg2, arg3) {
  
  }
  
  functionName.call(obj, arg1, arg2, arg3);
  
  functionName.apply(obj, [arg1, arg2, arg3]);
  
  var bound = functionName.bind(obj);
  bound(arg1, arg2, arg3);