'Passing None means any key, or any modifier'

def ungrab_key(self, key, modifiers):

    if (key is None):
        key = xcffib.xproto.Atom.Any
    if (modifiers is None):
        modifiers = xcffib.xproto.ModMask.Any
    self.conn.conn.core.UngrabKey(key, self.wid, modifiers)
