public override void TestWriteReadMerge()
{
AssumeFalse("impersonation isnt good enough", Codec is Lucene3xCodec);
// this test tries to switch up between the codec and another codec.
// for 3.x: we currently cannot take an index with existing 4.x segments
// and merge into newly formed 3.x segments.
base.TestWriteReadMerge();
}