/// <summary>
/// Returns the parent <see cref="TcpConnection"/> of the given <see cref="UdpConnection"/>.
/// </summary>
/// <param name="udpConnection">The <see cref="UdpConnection"/> whose parent <see cref="TcpConnection"/> to return.</param>
/// <returns>The <see cref="TcpConnection"/> which owns the given <see cref="UdpConnection"/>.</returns>
public TcpConnection this[UdpConnection udpConnection]
{
get { return(connections.SingleOrDefault(c => c.Value.Count(uc => uc.GetHashCode().Equals(udpConnection.GetHashCode())) > 0).Key); }
}