public synchronized T get(long key) {
		KeyedSoftReference<T> ref = map.get(key);
		if (ref != null) {
			T obj = ref.get();
			if (obj == null) {
				map.remove(key);
			}
			else {
				if (obj.checkIsValid()) {
					addToHardCache(obj);
					return obj;
				}
				map.remove(key);
			}
		}
		return null;
	}
Retrieves the database object with the given key from the cache.
@param key the key of the object to retrieve.
@return the cached object or null if the object with that key is not currently cached.
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/DBObjectCache.java