syntax_data: {"ast_node_type":"other","tokens":[{"end":15,"kind":"keyword","start":0,"text":"assert_eq!("}]}
source_snippet:     assert_eq!(
context_before:     imported_src_file.add_external_src(|| Some(unnormalized.to_string()));
context_after:         imported_src_file.external_src.borrow().get_source().unwrap(),