syntax_data: {"ast_node_type":"other","tokens":[{"end":84,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:                 // Ideally we would walk the existential predicates here or at least
context_before:             ty::Dynamic(lhs_preds, ..) => {
context_after:                 // compare their length. But considering that the relevant `Relate` impl