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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 kill_all():
 """When polysh quits, we kill all the remote shells we started"""

    for i in dispatchers.all_instances():
        try:
            os.kill(-i.pid, signal.SIGKILL)
        except OSError:
            # The process was already dead, no problem
            pass