syntax_data: {"ast_node_type":"other","tokens":[{"end":84,"kind":"keyword","start":0,"text":"write!(self,"}]}
source_snippet:                     write!(self, "Opaque({:?}, {})", def_id, args.print_as_list())?;
context_before:                     // FIXME(eddyb) print this with `print_def_path`.
context_after:                     return Ok(());