function done( error, results ) {
		var out;
		if ( !error ) {
			out = transform( results, opts.iterations );
		}
		// Avoid releasing the zalgo:
		nextTick( onTick );

		/**
		* Callback invoked upon the next tick.
		*
		* @private
		* @returns {void}
		*/
		function onTick() {
			if ( error ) {
				return cb( error );
			}
			cb( null, out );
		}
	}
Callback invoked upon completion.

@private
@param {(Error|null)} error - error object
@param {ArrayArray} results - raw results