animate margin property

[hpet]

Hello,

I am trying to animate a margin-left property.
From the docs I see margin is among things that can be animated, I just can't make it to work.
Does anyone have any example?

Thank you!

[Animal]

Ext.lib.Anim.motion(myDomElement, {
    'margin-left': {to: 200},
    duration: 1.0,
    easing: 'easeNone'
}).animate();