use std::collections::HashMap;
use std::hash::Hash;
const NIL: usize = usize::MAX;
struct Node<K, V> {
import com.github.benmanes.caffeine.cache.CacheLoader;
import com.github.benmanes.caffeine.cache.Caffeine;
import com.github.benmanes.caffeine.cache.LoadingCache;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;