syntax_data: {"ast_node_type":"other","tokens":[{"end":78,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:             // Track all entries ever enqueued to avoid duplicating work. This
context_before:             queue: Vec<(Option<State>, Option<State>)>,
context_after:             // gives us a guarantee that a given (a_state, b_state) pair will