|                           |  | var stream = require('stream')
function isStream (obj) {  return obj instanceof stream.Stream}
function isReadable (obj) {  return isStream(obj) && typeof obj._read == 'function' && typeof obj._readableState == 'object'}
function isWritable (obj) {  return isStream(obj) && typeof obj._write == 'function' && typeof obj._writableState == 'object'}
function isDuplex (obj) {  return isReadable(obj) && isWritable(obj)}
module.exports            = isStreammodule.exports.isReadable = isReadablemodule.exports.isWritable = isWritablemodule.exports.isDuplex   = isDuplex
 |