syntax_data: {"ast_node_type":"other","tokens":[{"end":72,"kind":"keyword","start":0,"text":"ty::Invariant"}]}
source_snippet:             ty::Invariant => self.infcx.equate_regions(a, b, self.span),
context_before:             ty::Contravariant => self.infcx.sub_regions(a, b, self.span),
context_after:             ty::Bivariant => {