public boolean remove(K key, V value) {
		C collection = backing.get(key);
		if (collection != null && collection.remove(value) && collection.isEmpty()) {
			backing.remove(key);
			return true;
		}
		return false;
	}
Removes a key-value pair.

@param key
		Key.
@param value
		Value.

@return {@code true} if key-value pair was removed.
recaf-core/src/main/java/software/coley/recaf/util/MultiMap.java