pub trait AddressL4: Address {
fn p4_index(&self) -> usize;
fn p3_index(&self) -> usize;
fn p2_index(&self) -> usize;
fn p1_index(&self) -> usize;
fn from_page_table_indices(
p4_index: usize,
p3_index: usize,
p2_index: usize,
p1_index: usize,
offset: usize
) -> Self;
}