syntax_data: {"ast_node_type":"other","tokens":[{"end":82,"kind":"keyword","start":0,"text":"(Variance::Contravariant,"}]}
source_snippet:             (Variance::Contravariant, Variance::Bivariant) => Variance::Bivariant,
context_before:             (Variance::Contravariant, Variance::Invariant) => Variance::Invariant,