function factory( options ) {
	var opts;
	if ( arguments.length > 0 ) {
		if ( !isObject( options ) ) {
			throw new TypeError( format( 'invalid argument. Options argument must be an object. Value: `%s`.', options ) );
		}
		opts = assign( {}, options );
	} else {
		opts = {};
	}
	return createStream;

	/**
	* Returns an "empty" readable stream.
	*
	* @private
	* @throws {TypeError} options argument must be an object
	* @throws {TypeError} must provide valid options
	* @returns {EmptyStream} Stream instance
	*/
	function createStream() {
		return new EmptyStream( opts );
	}
}
Returns a function for creating "empty" readable streams.

@param {Options} [options] - stream options
@param {boolean} [options.objectMode=false] - specifies whether a stream should operate in object mode
@throws {TypeError} options argument must be an object
@returns {Function} stream factory

@example
var opts = {
    'objectMode': false
};

var createStream = factory( opts );

// Create 10 identically configured streams...
var streams = [];
var i;
for ( i = 0; i < 10; i++ ) {
    streams.push( createStream() );
}