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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 strip_prompt(self, a_string):
 """ Strip 'Done' from command output """

        output = super(NetscalerSSH, self).strip_prompt(a_string)
        lines = output.split(self.RESPONSE_RETURN)
        if "Done" in lines[-1]:
            return self.RESPONSE_RETURN.join(lines[:-1])
        else:
            return output