Function sprs::prod::csr_mul_csvec

pub fn csr_mul_csvec<N, I, Iptr>(
    lhs: CsMatViewI<'_, N, I, Iptr>, 
    rhs: CsVecViewI<'_, N, I>
) -> CsVecI<N, I> where
    N: MulAcc + Zero + PartialEq + Clone,
    I: SpIndex,
    Iptr: SpIndex, 

CSR-vector multiplication