syntax_data: {"ast_node_type":"other","tokens":[{"end":91,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:         // `false` we don't know whether we came from `1` or `2`, hence we can't know where
context_before:         // took `(2, _)` in the same set of candidates, when we reach the block that tests
context_after:         // to branch on failure.