syntax_data: {"ast_node_type":"other","tokens":[{"end":43,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:     // different string gets a different #:
context_before:     assert_eq!(i.intern_byte_str(b"dog"), ByteSymbol::new(0));
context_after:     assert_eq!(i.intern_byte_str(b"cat"), ByteSymbol::new(1));