Returns a CustomBounce ease instance.
GreenSock Docs (HTML5/JS)
CustomBounce.create()
CustomBounce.create( ID:String, vars:Object ) : CustomBounce
Creates a CustomBounce ease based on the parameters you provide.
Parameters
ID: String
An ID (name) that can be used to identify this CustomBounce instance, like "superBounce".
vars: Object
configuration options for the ease for setting its strength (bounciness), and squash.
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Returns : CustomBounce

Details
This method creates a new CustomBouunce ease and a separate ease to handle the squash and stretch (optional).
For the bounce and the squash/stretch to work together use two tweens; one for the position ("y"), and the other for the scaleX/scaleY, with both running at the same time:
//Create a custom bounce ease:
CustomBounce.create("myBounce", {strength:0.6, squash:3, squashID:"myBounce-squash"});
//do the bounce by affecting the "y" property.
TweenMax.from(".class", 2, {y:-200, ease:"myBounce"});
//and do the squash/stretch at the same time:
TweenMax.to(".class", 2, {scaleX:140, scaleY:60, ease:"myBounce-squash", transformOrigin:"center bottom"});
See the Pen CustomBounce from GreenSock by GreenSock (@GreenSock) on CodePen.