Function __action165 

fn __action165<'a>(
    handler: &Handler,
    (_, at, _): (usize, SyntaxNode<'a>, usize),
    (_, n, _): (usize, SyntaxNode<'a>, usize),
    (_, list, _): (usize, Option<SyntaxNode<'a>>, usize),
) -> SyntaxNode<'a>