Override common ACEs of object

pluginProto.onCreate = function ()
{
    // Override the 'set width' action
    pluginProto.acts.SetWidth = function (w)
    {
        if (this.width !== w)
        {
            this.width = w;
            this.text_changed = true;    // also recalculate text wrapping
            this.set_bbox_changed();
        }
    };

See the official text plugin.
The common ACEs could be found in commonace.js