1  'use strict';
 2  
 3  if (typeof process === 'undefined' ||
 4      !process.version ||
 5      process.version.indexOf('v0.') === 0 ||
 6      process.version.indexOf('v1.') === 0 && process.version.indexOf('v1.8.') !== 0) {
 7    module.exports = { nextTick: nextTick };
 8  } else {
 9    module.exports = process
10  }
11  
12  function nextTick(fn, arg1, arg2, arg3) {
13    if (typeof fn !== 'function') {
14      throw new TypeError('"callback" argument must be a function');
15    }
16    var len = arguments.length;
17    var args, i;
18    switch (len) {
19    case 0:
20    case 1:
21      return process.nextTick(fn);
22    case 2:
23      return process.nextTick(function afterTickOne() {
24        fn.call(null, arg1);
25      });
26    case 3:
27      return process.nextTick(function afterTickTwo() {
28        fn.call(null, arg1, arg2);
29      });
30    case 4:
31      return process.nextTick(function afterTickThree() {
32        fn.call(null, arg1, arg2, arg3);
33      });
34    default:
35      args = new Array(len - 1);
36      i = 0;
37      while (i < args.length) {
38        args[i++] = arguments[i];
39      }
40      return process.nextTick(function afterTick() {
41        fn.apply(null, args);
42      });
43    }
44  }
45