Function.prototype.call2 = function(context, ...args) {
  context = (context === undefined || context === null) ? window : context
  context.__fn = this
  let result = context.__fn(...args)
  delete context.__fn
  return result
}
Function.prototype.apply2 = function(context, args) {
  context = (context === undefined || context === null) ? window : context
  context.__fn = this
  let result = context.__fn(...args)
  delete context.__fn
  return result
}
Function.prototype.bind2 = function(context, ...args1) {
  context = (context === undefined || context === null) ? window : context
  let _this = this
  return function(...args2) {
    context.__fn = _this
    let result = context.__fn(...[...args1, ...args2])
    delete context.__fn
    return result
  }
}