syntax_data: {"ast_node_type":"other","tokens":[{"end":59,"kind":"keyword","start":0,"text":"source_files:"}]}
source_snippet:     source_files: monotonic::MonotonicVec<Arc<SourceFile>>,
context_before: struct SourceMapFiles {
context_after:     stable_id_to_source_file: UnhashMap<StableSourceFileId, Arc<SourceFile>>,