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]

def cumulative_var(self):
        """
        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]
        """
        from .. import extensions
        agg_op = "__builtin__cum_var__"
        return SArray(_proxy = self.__proxy__.builtin_cumulative_aggregate(agg_op))