syntax_data: {"ast_node_type":"other","tokens":[{"end":26,"kind":"keyword","start":0,"text":"CyclicConst(I::Const),"}]}
source_snippet:     CyclicConst(I::Const),
context_before:     CyclicTy(I::Ty),
context_after:     ProjectionMismatched(ExpectedFound<I::DefId>),