syntax_data: {"ast_node_type":"other","tokens":[{"end":49,"kind":"keyword","start":0,"text":"self.to_string().into_diag_arg(&mut"}]}
source_snippet:         self.to_string().into_diag_arg(&mut None)
context_before:     fn into_diag_arg(self, _: &mut Option<std::path::PathBuf>) -> rustc_errors::DiagArgValue {
context_after:     }