package myBtree; import java.util.function.Consumer; import java.util.Optional; final public class Empty> extends Btree { public Empty() {} @Override public void display(Consumer func) {} @Override public Btree add(T data) { return new Node(data, this, this); } @Override public Optional> find(T data) { return Optional.empty(); } @Override public boolean isEmpty() { return true; } @Override public Btree remove(T data) { return this; } }