Proxy Command
The ProxyCommand is a convenience class that will search the command container hierarchy
for a command with the same id and invoke it. This is useful when you have nested containers
and you need to invoke a command defined higher in the hierarchy. You could do it manually
by monitoring the container yourself, however this approach greatly simplifies it. The proxy
will use the same configuration as the real command and will automatically update if either the
command or the container hierarchy changes.
NOTE: While the proxy monitors changes to the state of the real command (i.e. enabled and
visible) it doesn't track changes to it's faces. So if you alter faces programmatically
on the real command, the proxy won't pick them up.