code: def cumulative_var(self):
          
          from .. import extensions
          agg_op = "__builtin__cum_var__"
          return SArray(_proxy = self.__proxy__.builtin_cumulative_aggregate(agg_op))
docs: Return the cumulative variance of the elements in the SArray.
  
          Returns an SArray where each element in the output corresponds to the
          variance of all the elements preceding and including it. The SArray is
          expected to be of numeric type, or a numeric vector type.
  
          Returns
          -------
          out : SArray[int, float]
  
          Notes
          -----
           - Missing values are ignored while performing the cumulative
             aggregate operation.
  
          Examples
          --------
          >>> sa = SArray([1, 2, 3, 4, 0])
          >>> sa.cumulative_var()
          dtype: float
          rows: 3
          [0.0, 0.25, 0.6666666666666666, 1.25, 2.0]