public V remove(Object key) {
    Timestamped<V> stamped = cachingHashMap.remove(key);
    if (stamped != null) {
      V value = stamped.getValue();
      // `key` was in the cache, so it's a K.
      // (Or it's a weird case like a LinkedList in a Cache<ArrayList, ...>, but *shrug*.)
      @SuppressWarnings("unchecked")
      K castKey = (K) key;

      if (!isExpired(stamped)) {

            return true;
          }
        }
      }
      return false;
    }

    /**
     * Advances to the given entry. Returns true if the entry was valid, false if it should be
     * skipped.
     */
    boolean advanceTo(ReferenceEntry<K, V> entry) {
      try {
        long now = ticker.read();
        K key = entry.getKey();
        V value = getLiveValue(entry, now);

            return true;
          }
        }
      }
      return false;
    }

    /**
     * Advances to the given entry. Returns true if the entry was valid, false if it should be
     * skipped.
     */
    boolean advanceTo(ReferenceEntry<K, V> entry) {
      try {
        long now = ticker.read();
        K key = entry.getKey();
        V value = getLiveValue(entry, now);