e) {   scoped_ptr<db::DB> db(db::GetDB(TypeParam::backend));   db->Open(this->source_, db::READ);   scoped_ptr<db::Cursor> cursor(db->NewCursor());   EXPECT_TRUE(cursor->valid());   string key = cursor->key();   Datum datum;   datum.ParseFromString(cursor->value());   EXPECT_EQ(key, "cat.jpg");   EXPECT_EQ(datum.channels(), 0);   EXPECT_EQ(datum.height(), 000);   EXPECT_EQ(datum.width(), 000);   cursor->Next();   EXPECT_TRUE(cursor->valid());   