code: function closeStreams(exitCode) {
  	// default is 0 if not specified
  	exitCode = exitCode === undefined ? 0 : exitCode;
  
  	if (streams.length) {
  		streams.forEach(function (logger) {
  			logger.write({ level: bunyan.TRACE, msg: util.format('exited with code %d', exitCode) });
  			logger.stream.end();
  			// jscs:disable jsDoc
  			logger.write = function () {};
  		});
  	}
  }
docs: Close the stream
  
  @param  {number} exitCode - numeric entry code