public boolean putAll(K key, @Nonnull Collection<? extends V> values) {
		return get(key).addAll(values);
	}
Puts a collection of values in the map.

@param key
		Key.
@param values
		Values.

@return {@code true} if any value was added to the collection.
recaf-core/src/main/java/software/coley/recaf/util/MultiMap.java