syntax_data: {"ast_node_type":"other","tokens":[{"end":54,"kind":"keyword","start":0,"text":")"}]}
source_snippet:     ) -> BlockAnd<&'b mut [&'c mut Candidate<'tcx>]> {
context_before:         start_block: BasicBlock,
context_after:         // Choose a match pair from the first candidate, and use it to determine a