<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_focus_client(self):

 """Return current client with focus, if any"""

        widget = QApplication.focusWidget()
        for client in self.get_clients():
            if widget is client or widget is client.get_control():
                return client