Код: Выделить всё
public bool Equals(Permissions that)
{
if (Groups == null && that.Groups != null || Groups != null && that.Groups == null) return false;
if (Users == null && that.Users != null || Users != null && that.Users == null) return false;
if (Groups != null && Users != null)
return Groups.SequenceEqual(that.Groups) && Users.SequenceEqual(that.Users);
return Groups != null ? Groups.SequenceEqual(that.Groups) : Users.SequenceEqual(that.Users);
}
Подробнее здесь: https://stackoverflow.com/questions/630 ... -for-nulls