{"ast_node_type":"other","tokens":[{"end":99,"kind":"keyword","start":0,"text":"//"}]}
    // they are already added in `used_items`. We could just scan `used_items`, but that's a linear
    // overhead, we have a special optimization that avoids adding items to `mentioned_items` when
    // scan and not very efficient. Furthermore we can only do that *after* monomorphizing the