message: Move Num use to module
diff: @@ -30,7 +30,7 @@ use std::ops::{
  };
  use std::slice::{Iter, IterMut};
  -use num_traits::{Float, Num, Signed, Zero};
  +use num_traits::{Float, Signed, Zero};
  use crate::array_backend::Array2;
  use crate::errors::StructureError;
  @@ -1338,6 +1338,7 @@ where
  mod alga_impls {
  use super::*;
  use alga::general::*;
  + use num_traits::Num;
  impl<N, I> AbstractMagma<Additive> for CsVecI<N, I>
  where
  