syntax_data: {"ast_node_type":"other","tokens":[{"end":72,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:         // the args owned by the opaque are going to always be duplicate
context_before:         // Only check that the parent generics of the TAIT/RPIT are unique.
context_after:         // lifetime params for RPITs, and empty for TAITs.