public void Return <TKey, TValue>(IEnumerable <ConcurrentDictionary <TKey, TValue> > items)
 => ConcurrentDictionaryPool <TKey, TValue> .Return(items);
 public void Return <TKey, TValue>(ConcurrentDictionary <TKey, TValue> item)
 => ConcurrentDictionaryPool <TKey, TValue> .Return(item);
 public void Return <TKey, TValue>(params ConcurrentDictionary <TKey, TValue>[] items)
 => ConcurrentDictionaryPool <TKey, TValue> .Return(items);
 public ConcurrentDictionary <TKey, TValue> ConcurrentDictionary <TKey, TValue>()
 => ConcurrentDictionaryPool <TKey, TValue> .Get();