{"ast_node_type":"other","tokens":[{"end":75,"kind":"keyword","start":0,"text":"//"}]}
        // efficiency even for the common case where the key is in the map.
        // We have "NLL problem case #3" here, which cannot be worked around without loss of
        // <https://rust-lang.github.io/rfcs/2094-nll.html#problem-case-3-conditional-control-flow-across-functions>