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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 format_cli(self, value):
 """ Build a single parameter argument. :return: list of CLI strings -- not escaped. If the parameter should not be expressed, returns None. :rtype: list[str]|None """

        if value is None or (self.type == 'flag' and not value):
            return None
        pass_as_bits = text_type(self.pass_as or self.default_pass_as).split()
        env = dict(name=self.name, value=value, v=value)
        return [bit.format(**env) for bit in pass_as_bits]