internal override bool ContainsColumn(DataColumn column) { return(_key.ContainsColumn(column)); }
internal override bool ContainsColumn(DataColumn column) { return(parentKey.ContainsColumn(column) || childKey.ContainsColumn(column)); }
internal override bool ContainsColumn(DataColumn column) => _parentKey.ContainsColumn(column) || _childKey.ContainsColumn(column);