pub fn deallocating_end(self) {
        let mut edge = self.forget_node_type();
        while let Some(parent_edge) = unsafe { edge.into_node().deallocate_and_ascend() } {
            edge = parent_edge.forget_node_type();
        }
    }
Moves the leaf edge handle to the next leaf edge and returns the key and value
in bet
benchmarks/haystacks/code/rust-library.rs