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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 continuous_future(self, root_symbol_str, offset=0, roll='volume', adjustment='mul'):
 """Create a specifier for a continuous contract. Parameters root_symbol_str : str The root symbol for the future chain. offset : int, optional The distance from the primary contract. Default is 0. roll_style : str, optional How rolls are determined. Default is 'volume'. adjustment : str, optional Method for adjusting lookback prices between rolls. Options are 'mul', 'add', and None. Default is 'mul'. Returns ------- continuous_future : ContinuousFuture The continuous future specifier. """

        return self.asset_finder.create_continuous_future(
            root_symbol_str,
            offset,
            roll,
            adjustment,
        )