public void AddRange(Type type, IEnumerable<MemberMetadata> metadatas) { type.ThrowIfNull("type", "Parameter cannot be null."); if (_container.ContainsKey(type)) { _container[type].AddRange(metadatas); } else { SafeCollection<MemberMetadata> holder = new SafeCollection<MemberMetadata>(); holder.AddRange(metadatas); _container.TryAdd(type, holder); } }