Path file = new Path(dir, "file");
DFSTestUtil.createFile(hdfs, file, BLOCKSIZE, REPLICATION, seed);
// 1. append without closing stream --> create snapshot
HdfsDataOutputStream out = appendFileWithoutClosing(file, BLOCKSIZE);
out.hsync(EnumSet.of(SyncFlag.UPDATE_LENGTH));
SnapshotTestHelper.createSnapshot(hdfs, dir, "s0");
out.close();
// check: an INodeFileUnderConstructionWithSnapshot should be stored into s0's
// deleted list, with size BLOCKSIZE*2