guava/src/com/google/common/util/concurrent/AtomicLongMap.java
public static <K> AtomicLongMap<K> create(Map<? extends K, ? extends Long> m) {
    AtomicLongMap<K> result = create();
    result.putAll(m);
    return result;
  }
public static <K> AtomicLongMap<K> create(Map<? extends K, ? extends Long> m) {
    AtomicLongMap<K> result = create();
    result.putAll(m);
    return result;
  }
Creates an {@code AtomicLongMap} with the same mappings as the specified {@code Map}.