/// <summary>関係を断つ</summary>
/// <param name="related">関係者</param>
public void Remove(INetworkable related)
{
if (!Parents.Contains(related) && !Children.Contains(related))
{
return;
}
Parents = Parents.Except(new[] { related });
Children = Children.Except(new[] { related });
related.Remove(this);
}