famo.us - how to do loops, and callbacks using $timeline? -

are these functionalities built service somewhere? here's sample context:

html

<fa-modifier fa-opacity="opacitymod(testtimeline.get())">... 

js

$scope.testtimeline = new transitionable(0); $scope.opacitymod = $testtimeline([     [0, 0, easing.inoutexpo],     [1, 1] ]); $scope.testtimeline.set(1, {     duration: 500,     curver: 'easeinout' }); 

couldn't find these in docs or reading src. ideas had were:

• loops - setinterval or re-run animation on callback
• callback - settimeout @ same time testtimeline.set called same duration within same scope

ended doing callback on transitionable's 'set' , re-running function afterwards. here's sample:

function runloop(){     $scope.testtimeline.set(1, {duration:...,curve:...}, function() {         $scope.testtimeline.set(0, {duration:....,curve....}, runloop);     }); } runloop(); 

note runs loop again backwards. (i wanted affect). still open other solutions