syntax_data: {"ast_node_type":"other","tokens":[{"end":83,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:         // This might be reachable (via `pretty_print_dyn_existential`) even though
context_before:     fn print_region(&mut self, _region: ty::Region<'_>) -> Result<(), PrintError> {
context_after:         // `<Self As PrettyPrinter>::should_print_region` returns false. See #144994.