syntax_data: {"ast_node_type":"other","tokens":[{"end":64,"kind":"keyword","start":0,"text":"assert_eq!(sm.span_to_snippet(span),"}]}
source_snippet:     assert_eq!(sm.span_to_snippet(span), Ok("…".to_string()));
context_before:     let span = sm.next_point(span);
context_after:     assert_eq!(span.lo().0, 1);