Can't resize keikai with Clients.resize()

Steps to Reproduce

1. run the attached zul
2. click the button

Current Result

zk.wpd:20958 Uncaught TypeError: child.beforeParentChanged_ is not a function
at init.appendChild (zk.wpd:20958)
at init.$supers (zk.wpd:12982)
at init.appendChild (zk.wpd:43780)
at init.getToolbarPanel (zss.wpd:13170)
at init.clearCachedSize_ (zss.wpd:13157)
at init.beforeSize (zk.wpd:29200)
at _invoke (zk.wpd:16465)
at init.fire (zk.wpd:16448)
at _fire (zk.wpd:16591)
at Object.fireDown (zk.wpd:16808)

Expected Result

spreadsheet can resize to fit the parent height