/// <summary>
/// Gets the entities assignable from.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="btr">The BTR.</param>
/// <param name="mode">The mode.</param>
/// <param name="includingErased">if set to <c>true</c> [including erased].</param>
/// <param name="openObjectsOnLockedLayers">if set to <c>true</c> [open objects on locked layers].</param>
/// <returns></returns>
public static IEnumerable <T> GetEntitiesAssignableFrom <T>(this BlockTableRecord btr,
OpenMode mode = OpenMode.ForRead, bool includingErased = false, bool openObjectsOnLockedLayers = false)
where T : Entity
{
return(btr.GetEntitiesAssignableFrom <T>(btr.Database.TransactionManager.TopTransaction, mode,
includingErased, openObjectsOnLockedLayers));
}