// now open reader again & set norm for doc 0 (writes to _0_2.s0)
reader = IndexReader.open(dir, false);
reader.setNorm(0, "content", (float) 2.0);
reader.close();
assertFalse("failed to remove first generation norms file on writing second generation",
dir.fileExists("_0_1.s0"));
dir.close();
}