pub trait ScalableMut {
type Vec;
fn resize_mut(&mut self, size: (usize, usize), shape: Shape);
fn add_col_mut(&mut self, v: &Self::Vec);
fn add_row_mut(&mut self, v: &Self::Vec);
}
pub trait ScalableMut {
type Vec;
fn resize_mut(&mut self, size: (usize, usize), shape: Shape);
fn add_col_mut(&mut self, v: &Self::Vec);
fn add_row_mut(&mut self, v: &Self::Vec);
}