internal static string MakeAvoidString(Avoid avoid)
{
var sb = new StringBuilder();
foreach(Avoid avoidFlag in Enum.GetValues(typeof(Avoid)))
{
if(avoidFlag != 0 && ((avoid & avoidFlag) == avoidFlag))
sb.Append((sb.Length > 0 ? "|" : "") + avoidFlag.ToString());
}
return sb.ToString();
}