@Override
    protected void delete(final String storageKey) throws ResourceIOException {
        cache.remove(storageKey);
    }
Constructs a storage backend using the provided Ehcache
with the given configuration options, but using an alternative
cache entry serialization strategy.
@param cache where to store cached origin responses
@param config cache storage configuration options - note that
  the setting for max object size <b>will be ignored</b> and
  should be configured in the Ehcache instead.
@param serializer alternative serialization mechanism
httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/ehcache/EhcacheHttpCacheStorage.java