public static bool IsNull(PPItemBase instance)
{
if (instance == null) return true;
if (instance is PPItemBlock)
return ((instance as PPItemBlock).Model == null);
if (instance is PPItemNpt)
return ((instance as PPItemNpt).Model == null);
return true;
}
/// <summary>
/// Specifies whether the PPItemBase fits (or partially fits) in the range specifed by this PPRange
/// </summary>
/// <param name="start"></param>
/// <param name="end"></param>
/// <returns></returns>
public bool IsInRange(PPItemBase item)
{
return !(item.End < Start || item.Start > End);
}
