The frame index is reset when I call 'play' on an Animation, but there is also a function called 'restart'. How do I 'resume'?

I would like the line 
            this._frameIndex = 0;
in Phaser.Animation.prototype.play changed to:
            this._frameIndex = this._frameIndex || 0; // Do not reset frame.

It also seems that it resets the frame time timer. That, combined with the fact that this change will break some games, I request a 'resume' function.