type Row = {
children: &Array<Widget>,
spacing: &f64,
padding: &Padding,
width: &Length,
height: &Length,
valign: &VAlign
};
val row: fn(
?#spacing: &f64,
?#padding: &Padding,
?#width: &Length,
?#height: &Length,
?#valign: &VAlign,
children: &Array<Widget>
) -> Widget