Clean piped input

foo.js

var stream = require('stream');
var util = require('util');

function Clean(options) {
  if (!(this instanceof Clean)) {
    return new Clean(options);
  }
  stream.Transform.call(this, options);
}

util.inherits(Clean, stream.Transform);

Clean.prototype._transform = function (chunk, enc, done) {
  this.push(chunk.toString().replace(/aN;(NaN|0)f/,''), 'utf8');
  done();
};

module.exports = Clean;%