syntax_data: {"ast_node_type":"other","tokens":[{"end":74,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// Combining Definition- and Use-Site Variance" published in PLDI'11.
context_before:     /// Source: Figure 1 of "Taming the Wildcards:
context_after:     pub fn xform(self, v: Variance) -> Variance {