syntax_data: {"ast_node_type":"other","tokens":[{"end":67,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// and hence the outermost type is `Invariant` with respect to
context_before:     /// variance of `Vec<i32>` is `Contravariant.xform(Invariant)`,
context_after:     /// `Vec<i32>` (and its `i32` argument).