Documentation for Grid.Toolbar methods?

[Dan]

So I've spent the better part of my afternoon trying to find documentation or examples on how .Toolbar should work with a Kendo MVC grid and I've come up empty.  I've found its easy enough for a predefined command type (command.Create for example) but I'm trying to find documentation on how commands.Custom is supposed to work.  Does anyone have any documentation?  There was no mention of the Toolbar method at all in the API documentation.