pub fn ewm_var<I, T>(
xs: I,
alpha: T,
adjust: bool,
bias: bool,
min_periods: usize,
ignore_nulls: bool,
) -> PrimitiveArray<T>where
I: IntoIterator<Item = Option<T>> + Clone,
I::IntoIter: TrustedLen,
T: Float + NativeType + AddAssign + MulAssign + DivAssign,