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package jdk.internal.vm.compiler.collections;

Unmodifiable memory efficient map. See EconomicMap for the underlying data structure and its properties. 
Since:
19.0/**
 * Unmodifiable memory efficient map. See {@link EconomicMap} for the underlying data structure and
 * its properties.
 *
 * @since 19.0
 */
public interface UnmodifiableEconomicMap<K, V> {

    
Returns the value to which key is mapped, or null if this map contains no mapping for key. The key must not be null. 
Since:
19.0/**
     * Returns the value to which {@code key} is mapped, or {@code null} if this map contains no
     * mapping for {@code key}. The {@code key} must not be {@code null}.
     *
     * @since 19.0
     */
    V get(K key);

    
Returns the value to which key is mapped, or defaultValue if this map contains no mapping for key. The key must not be null. 
Since:
19.0/**
     * Returns the value to which {@code key} is mapped, or {@code defaultValue} if this map
     * contains no mapping for {@code key}. The {@code key} must not be {@code null}.
     *
     * @since 19.0
     */
    default V get(K key, V defaultValue) {
        V v = get(key);
        if (v == null) {
            return defaultValue;
        }
        return v;
    }

    
Returns true if this map contains a mapping for key. Returns always false if the key is null. 
Since:
19.0/**
     * Returns {@code true} if this map contains a mapping for {@code key}. Returns always
     * {@code false} if the {@code key} is {@code null}.
     *
     * @since 19.0
     */
    boolean containsKey(K key);

    
Returns the number of key-value mappings in this map.
Since:
19.0/**
     * Returns the number of key-value mappings in this map.
     *
     * @since 19.0
     */
    int size();

    
Returns true if this map contains no key-value mappings. 
Since:
19.0/**
     * Returns {@code true} if this map contains no key-value mappings.
     *
     * @since 19.0
     */
    boolean isEmpty();

    
Returns a Iterable view of the values contained in this map. 
Since:
19.0/**
     * Returns a {@link Iterable} view of the values contained in this map.
     *
     * @since 19.0
     */
    Iterable<V> getValues();

    
Returns a Iterable view of the keys contained in this map. 
Since:
19.0/**
     * Returns a {@link Iterable} view of the keys contained in this map.
     *
     * @since 19.0
     */
    Iterable<K> getKeys();

    
Returns a UnmodifiableMapCursor view of the mappings contained in this map. 
Since:
19.0/**
     * Returns a {@link UnmodifiableMapCursor} view of the mappings contained in this map.
     *
     * @since 19.0
     */
    UnmodifiableMapCursor<K, V> getEntries();
}