Strip 'Done' from command output

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