syntax_data: {"ast_node_type":"other","tokens":[{"end":62,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:     // debruijn depths depending on the binders we've entered.
context_before:     // Depends on `debruijn` because we may have types with regions of different
context_after:     cache: DelayedMap<(ty::DebruijnIndex, I::Ty), I::Ty>,