syntax_data: {"ast_node_type":"function","tokens":[{"end":42,"kind":"keyword","start":0,"text":"fn"}]}
source_snippet:     fn new(thir: &'a Thir<'tcx>) -> Self {
context_before: impl<'a, 'tcx> ThirPrinter<'a, 'tcx> {
context_after:         Self { thir, fmt: String::new() }