syntax_data: {"ast_node_type":"other","tokens":[{"end":66,"kind":"keyword","start":0,"text":"assert_eq!(loc2.file.name,"}]}
source_snippet:     assert_eq!(loc2.file.name, PathBuf::from("blork2.rs").into());
context_before:     let loc2 = sm.lookup_char_pos(BytePos(25));
context_after:     assert_eq!(loc2.line, 1);