.when(spyNN).openAndFetchMetaInfo(anyString(), anyLong(), anyLong());
is.openInfo();
// Seek to beginning forces a reopen of the BlockReader - otherwise it'll
// just keep reading on the existing stream and the fact that we've poisoned
// the block info won't do anything.
is.seek(0);
IOUtils.readFully(is, buf, 0, buf.length);
} finally {
cluster.shutdown();
}