public SqlHierarchyId GetAncestor(int n)
{
if (IsNull || _imp.GetLevel() < n)
{
return(Null);
}
if (n < 0)
{
throw new ArgumentOutOfRangeException("24011: SqlHierarchyId.GetAncestor failed because 'n' was negative.");
}
return(new SqlHierarchyId(_imp.GetAncestor(n)));
}