syntax_data: {"ast_node_type":"other","tokens":[{"end":85,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:         // `<Self As PrettyPrinter>::should_print_region` returns false. See #144994.
context_before:         // This might be reachable (via `pretty_print_dyn_existential`) even though
context_after:         Ok(())