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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _cleanupConnections(senderkey, signal):
 """Delete any empty signals for senderkey. Delete senderkey if empty."""

    try:
        receivers = connections[senderkey][signal]
    except:
        pass
    else:
        if not receivers:
            # No more connected receivers. Therefore, remove the signal.
            try:
                signals = connections[senderkey]
            except KeyError:
                pass
            else:
                del signals[signal]
                if not signals:
                    # No more signal connections. Therefore, remove the sender.
                    _removeSender(senderkey)