syntax_data: {"ast_node_type":"variable","tokens":[{"end":70,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let session_globals = SessionGlobals::new(edition, &[], None);
context_before:     if !SESSION_GLOBALS.is_set() {
context_after:         SESSION_GLOBALS.set(&session_globals, || SESSION_GLOBALS.with(f))