Function sparse_vstack 

pub fn sparse_vstack<T>(arrays: &[&CsrArray<T>]) -> SparseResult<CsrArray<T>>
where
    T: Float + SparseElement + Div<Output = T> + Debug + Copy + 'static,

Stack sparse matrices vertically (row-wise).

All matrices must have the same number of columns.

Arguments

• arrays - Slice of references to CsrArray matrices