syntax_data: {"ast_node_type":"other","tokens":[{"end":61,"kind":"keyword","start":0,"text":"if"}]}
source_snippet:                 if self.enqueued.insert((a_state, b_state)) {
context_before:             fn enqueue(&mut self, a_state: Option<State>, b_state: Option<State>) {
context_after:                     self.queue.push((a_state, b_state));