var stream = require('stream')

var util = require('util')

function ReadStream() {

stream.Readable.call(this)

}

util.inherits(ReadStream, stream.Readable)

ReadStream.prototype._read = function() {

this.push("I ")

this.push("Love ")

this.push("Imooc\n")

this.push(null)

}

function WritStream() {

stream.Writable.call(this)

this._cached = new Buffer('')

}

util.inherits(WritStream, stream.Writable)

WritStream.prototype._write = function(chunk, encode, cb) {

console.log(chunk.toString())

cb()

}

function TransformStream() {

stream.Transform.call(this)

}

util.inherits(TransformStream, stream.Transform)

TransformStream.prototype._transform = function(chunk, encode, cb) {

this.push(chunk)

cb()

}

TransformStream.prototype._flush = function(cb) {

this.push('Oh Yeah!')

cb()

}

var rs = new ReadStream()

var ws = new WritStream()

var ts = new TransformStream()

rs.pipe(ts).pipe(ws)