{"ast_node_type":"function","tokens":[{"end":66,"kind":"keyword","start":0,"text":"fn"}]}
    fn first_token(green_ref: &GreenNodeData) -> &GreenTokenData {
fn text_of_first_token(node: &SyntaxNode) -> TokenText<'_> {
        green_ref.children().next().and_then(NodeOrToken::into_token).unwrap()