public TreeIndex(string filePath, ObjectStorage <T> dataStorage, IComparer <T> comparer, bool duplicable = false)
{
_indexStorage = new ObjectStorage <IndexNode>(filePath);//, FileMode.Create);
_indexStorage.Initialize();
_dataStorage = dataStorage;
_duplicable = duplicable;
_comparer = comparer;
var firstOffset = _indexStorage.FirstOffset;
_root = firstOffset > 0 ? new Node <T>(firstOffset, null, _indexStorage, _dataStorage, _duplicable) : null;
}
