code: function validate( options ) {
  		var validator,
  			keys,
  			key,
  			err;
  
  		if ( !isObject( options ) ) {
  			return new TypeError( 'Stream()::invalid input argument. Options must be an object.' );
  		}
  		keys = Object.keys( options );
  		for ( var i = 0; i < keys.length; i++ ) {
  			key = keys[ i ];
  			validator = validators[ key ];
  			err = validator( options[key] );
  			if ( err ) {
  				return err;
  			}
  		}
  	}
docs: FUNCTIONS // 
  FUNCTION: validate( options )
  Validates stream options.
  
  @private
  @param {Object} options - Readable stream options
  @returns {Null|TypeError} null if valid or TypeError if invalid