The Map.Entry.equals() javadoc says "Returns true if the given object is also a map entry and the two entries represent the same mapping.", meaning any other metadata stored in cache entries (e.g. lifespan) must be ignored for the purpose of checking equality. In other words, this code should work regardless of what entries are stored in the cache or in the invocation context:

cache.entrySet().contains(new AbstractMap.SimpleEntry("k", "v"))