Function __action439 

fn __action439<'a>(
    handler: &Handler,
    (_, l, _): (usize, SyntaxNode<'a>, usize),
    (_, op, _): (usize, SyntaxNode<'a>, usize),
    (_, r, _): (usize, SyntaxNode<'a>, usize),
) -> SyntaxNode<'a>