lru *lru.LRU[string, *Stmt]
}

func (s *lruStore) Keys() []string {
	return s.lru.Keys()
}

func (s *lruStore) Get(key string) (*Stmt, bool) {
	stmt, ok := s.lru.Get(key)
	if ok && stmt != nil {
		<-stmt.prepared
	}
	return stmt, ok
}

func (s *lruStore) Set(key string, value *Stmt) {
	s.lru.Add(key, value)
}

func (s *lruStore) Delete(key string) {
	s.lru.Remove(key)
}

     */
    @Test
    public void testAll() throws Exception {
        final LruHashMap<String, String> lru = new LruHashMap<String, String>(3);
        lru.put("aaa", "111");
        lru.put("bbb", "222");
        lru.put("ccc", "333");
        assertThat(lru.get("aaa"), is("111"));
        Iterator<String> i = lru.keySet().iterator();
        assertThat(i.next(), is("bbb"));
        assertThat(i.next(), is("ccc"));

import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.Map;

/**
 * {@link HashMap} with an upper limit on the number of entries. When a new entry is added, the oldest entry is discarded using LRU if the limit is exceeded.
 * <p>
 * <strong>Thread-Safety:</strong> This class is <strong>NOT thread-safe</strong>.
 * It extends {@link LinkedHashMap} without synchronization. If multiple threads access

	lens := len(conn.Stmts.Keys())
	// Check if the number of stored statement keys is 0.
	if lens == 0 {
		// If the number is 0, it means there are no statements stored in the LRU cache.
		// The test fails and an error message is output.
		t.Fatalf("lru should not be empty")
	}
	// Wait for 40 seconds to give the statements in the cache enough time to expire.
	time.Sleep(time.Second * 40)

 */
public class LruHashSet<E> extends AbstractSet<E> implements Set<E>, java.io.Serializable {
    private static final long serialVersionUID = 1L;

    /**
     * The internal LRU hash map used to store elements.
     */
    private final LruHashMap<E, Object> map;

    // Dummy value to associate with an Object in the backing Map
    private static final Object PRESENT = new Object();

    /**

import java.util.Arrays;
import java.util.LinkedHashMap;
import java.util.Map;
import org.jspecify.annotations.Nullable;

/**
 * CompactLinkedHashMap is an implementation of a Map with insertion or LRU iteration order,
 * maintained with a doubly linked list through the entries. All optional operations (put and
 * remove) are supported. Null keys and values are supported.
 *