syntax_data: {"ast_node_type":"other","tokens":[{"end":45,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// which the first `Vec<i32>` appears is
context_before:     /// T` is covariant with respect to `T`, so the variance within
context_after:     /// `Contravariant.xform(Covariant)` or `Contravariant`. The same