pub trait WritableVertex {
// Required methods
fn add_input(&mut self, vertex_id: usize);
fn add_output(&mut self, vertex_id: usize);
fn remove_input(&mut self, vertex_id: usize);
fn remove_output(&mut self, vertex_id: usize);
}pub trait WritableVertex {
// Required methods
fn add_input(&mut self, vertex_id: usize);
fn add_output(&mut self, vertex_id: usize);
fn remove_input(&mut self, vertex_id: usize);
fn remove_output(&mut self, vertex_id: usize);
}