Mirror/Unity-Technologies-networking/Runtime/Telepathy/Message.cs

// incoming message queue of <connectionId, message>
// (not a HashSet because one connection can have multiple new messages)
namespace Telepathy
{
    public struct Message
    {
        public uint connectionId;
        public EventType eventType;
        public byte[] data;
        public Message(uint connectionId, EventType eventType, byte[] data)
        {
            this.connectionId = connectionId;
            this.eventType = eventType;
            this.data = data;
        }
    }
}