final ObjectId cmtid = ObjectId.fromString(
"803aec4aba175e8ab1d666873c984c0308179099");
assertEquals(cmtid, c.getCommitId());
// Verify the commit we just wrote is in the correct format.
ObjectDatabase odb = db.getObjectDatabase();
assertTrue("is ObjectDirectory", odb instanceof ObjectDirectory);
final XInputStream xis = new XInputStream(new FileInputStream(
((ObjectDirectory) odb).fileFor(cmtid)));
try {
assertEquals(0x78, xis.readUInt8());