Method invalidate

rls/src/main/java/io/grpc/rls/LruCache.java:48–48

Invalidates an entry for given key if exists. This operation will trigger EvictionListener with EvictionType#EXPLICIT. @return the previous value associated with key, otherwise null

(K key)

   * @return the previous value associated with key, otherwise {@code null}
   */
  @Nullable
  V invalidate(K key);

  /**