(Physics) Using Lua to set a Model's "bounce" properties

I am using the PhysicsStressTest example script ( https://github.com/urho3d/Urho3D/blob/master/bin/Data/LuaScripts/12_PhysicsStressTest.lua ) and I am trying to modify the “SpawnObject( )” function ( Line #216 ) to make the SmallBoxes bounce like a Tennis Ball or a Rubber Super Bouncy Ball. In the end; I’ll be using my own sphereical models in place of the SmallBoxes.

1: Tennis Ball / Basket Ball

2: Rubber Super Bouncy Ball ( like you buy for 25 - 50 cents at a store’s/laundry_mat’s kids toys dispencing machine )

I thought about using: body.restitution but I don’t know how to adjust that and/or the body.mass and/or the body.friction to accomplish a big bounce.