syntax_data: {"ast_node_type":"other","tokens":[{"end":75,"kind":"keyword","start":0,"text":"Covariant,"}]}
source_snippet:     Covariant,     // T<A> <: T<B> iff A <: B -- e.g., function return type
context_before: pub enum Variance {
context_after:     Invariant,     // T<A> <: T<B> iff B == A -- e.g., type of mutable cell