wrap a pipe chain in an exposed through stream

hmm.js

var through = require('through')

module.exports = function(chain){
  chain = chain();
  var s = through(function(data){
    if(!chain.write(data)) this.pause();
  });
  chain.on('drain',function(){
    s.resume();
  })
  chain.on('data',function(data){
   s.emit('data',data)
  });
  chain.on('end',function(){
   s.end();
  });
  return s;
}