syntax_data: {"ast_node_type":"other","tokens":[{"end":43,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:     // always compared less than `Some(_)`.
context_before:     // comparing them. Note that if a flag is not found, its position will be `None`, which
context_after:     let max_o = matches.opt_positions("O").into_iter().max();