code: @Nullable
    public <T> Cache<String, T> createCache(ConcurrentLinkedDeque<T> out) {
      return createCache(out, Ticker.systemTicker());
    }
docs: Creates a {@link Cache} configured by this instance.
  
  @param <T>
  the type of the instance being cached
  
  @param out
  a concurrent {@code Deque} to which previously cached items
  are added as they expire
  @return a {@link Cache} corresponding to this instance's values or
  {@code null} unless {@link #numEntries} is positive.