syntax_data: {"ast_node_type":"other","tokens":[{"end":76,"kind":"keyword","start":0,"text":"Some(\"on\""}]}
source_snippet:             Some("on" | "yes" | "y" | "true") | None => MirIncludeSpans::On,
context_before:         *slot = match v {
context_after:             Some("off" | "no" | "n" | "false") => MirIncludeSpans::Off,