@Override
	public Long floor(Long e) {
		return store.safe(lock.readLock(), () -> store.keys.floor(direction, e));
	}
This provides the implementation of {@link Map#keySet()} for {@link DBCachedObjectStore#asMap()}
Ghidra/Debug/ProposedUtils/src/main/java/ghidra/util/database/DBCachedObjectStoreKeySet.java