code: def continuous_future(self,
                            root_symbol_str,
                            offset=0,
                            roll='volume',
                            adjustment='mul'):
          
          return self.asset_finder.create_continuous_future(
              root_symbol_str,
              offset,
              roll,
              adjustment,
          )
docs: 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.