pub(crate) trait Walkable<'a, V: Visitor<'a>> {
// Required method
fn walk_ref(&'a self, visitor: &mut V) -> V::Result;
}
pub(crate) trait Walkable<'a, V: Visitor<'a>> {
// Required method
fn walk_ref(&'a self, visitor: &mut V) -> V::Result;
}