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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 check_enable_mode(self, check_string=""):
 """Check if in enable mode. Return boolean. :param check_string: Identification of privilege mode from device :type check_string: str """

        self.write_channel(self.RETURN)
        output = self.read_until_prompt()
        return check_string in output