syntax_data: {"ast_node_type":"other","tokens":[{"end":41,"kind":"keyword","start":0,"text":"source_file.add_external_src(||"}]}
source_snippet:         source_file.add_external_src(|| {
context_before:     pub fn ensure_source_file_source_present(&self, source_file: &SourceFile) -> bool {
context_after:             let FileName::Real(ref name) = source_file.name else {