依赖类库，不需要提交

-var Stream = require('stream').Stream;
-var util = require('util');
-
-module.exports = DelayedStream;
-function DelayedStream() {
-  this.source = null;
-  this.dataSize = 0;
-  this.maxDataSize = 1024 * 1024;
-  this.pauseStream = true;
-
-  this._maxDataSizeExceeded = false;
-  this._released = false;
-  this._bufferedEvents = [];
-}
-util.inherits(DelayedStream, Stream);
-
-DelayedStream.create = function(source, options) {
-  var delayedStream = new this();
-
-  options = options || {};
-  for (var option in options) {
-    delayedStream[option] = options[option];
-  }
-
-  delayedStream.source = source;
-
-  var realEmit = source.emit;
-  source.emit = function() {
-    delayedStream._handleEmit(arguments);
-    return realEmit.apply(source, arguments);
-  };
-
-  source.on('error', function() {});
-  if (delayedStream.pauseStream) {
-    source.pause();
-  }
-
-  return delayedStream;
-};
-
-DelayedStream.prototype.__defineGetter__('readable', function() {
-  return this.source.readable;
-});
-
-DelayedStream.prototype.resume = function() {
-  if (!this._released) {
-    this.release();
-  }
-
-  this.source.resume();
-};
-
-DelayedStream.prototype.pause = function() {
-  this.source.pause();
-};
-
-DelayedStream.prototype.release = function() {
-  this._released = true;
-
-  this._bufferedEvents.forEach(function(args) {
-    this.emit.apply(this, args);
-  }.bind(this));
-  this._bufferedEvents = [];
-};
-
-DelayedStream.prototype.pipe = function() {
-  var r = Stream.prototype.pipe.apply(this, arguments);
-  this.resume();
-  return r;
-};
-
-DelayedStream.prototype._handleEmit = function(args) {
-  if (this._released) {
-    this.emit.apply(this, args);
-    return;
-  }
-
-  if (args[0] === 'data') {
-    this.dataSize += args[1].length;
-    this._checkIfMaxDataSizeExceeded();
-  }
-
-  this._bufferedEvents.push(args);
-};
-
-DelayedStream.prototype._checkIfMaxDataSizeExceeded = function() {
-  if (this._maxDataSizeExceeded) {
-    return;
-  }
-
-  if (this.dataSize <= this.maxDataSize) {
-    return;
-  }
-
-  this._maxDataSizeExceeded = true;
-  var message =
-    'DelayedStream#maxDataSize of ' + this.maxDataSize + ' bytes exceeded.'
-  this.emit('error', new Error(message));
-};