exports = module.exports = require('./lib/_stream_readable.js');
  exports.Stream = exports;
  exports.Readable = exports;
  exports.Writable = require('./lib/_stream_writable.js');
  exports.Duplex = require('./lib/_stream_duplex.js');
  exports.Transform = require('./lib/_stream_transform.js');
  exports.PassThrough = require('./lib/_stream_passthrough.js');