'Force reload of all cmdsets in handler. This should be called
after _CACHED_CMDSETS have been cleared (normally this is
handled automatically by @reload).'

def reset(self):

    new_cmdset_stack = []
    for cmdset in self.cmdset_stack:
        if (cmdset.key == '_EMPTY_CMDSET'):
            new_cmdset_stack.append(cmdset)
        else:
            new_cmdset_stack.append(self._import_cmdset(cmdset.path))
    self.cmdset_stack = new_cmdset_stack
    self.update()
