syntax_data: {"ast_node_type":"other","tokens":[{"end":39,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:                 // smaller and simpler.
context_before:                 // opportunities to include them in test outcomes, making the match tree
context_after:                 self.expand_and_match_or_candidates(span, scrutinee_span, start_block, candidates)