final DocsFreqBlockIndexInput in = this.getIndexInput();
final DocsFreqBlockReader reader = in.getBlockReader();
reader.setNodeBlockIndex(in.index());
reader.setPosBlockIndex(in.index());
for (final int docId : docIds) {
if (reader.isExhausted()) {
reader.nextBlock();
}
assertEquals(docId, reader.nextDocument());