syntax_data: {"ast_node_type":"other","tokens":[{"end":67,"kind":"keyword","start":0,"text":"FxIndexMap<TestBranch<'tcx>,"}]}
source_snippet:         FxIndexMap<TestBranch<'tcx>, Vec<&'b mut Candidate<'tcx>>>,
context_before:         &'b mut [&'c mut Candidate<'tcx>],
context_after:     ) {