syntax_data: {"ast_node_type":"other","tokens":[{"end":93,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:             // which are then distinguished by testing whatever non-or patterns they contain.
context_before:             // Or-patterns are not tested directly; instead they are expanded into subcandidates,
context_after:             TestCase::Or { .. } => bug!("or-patterns should have already been handled"),