syntax_data: {"ast_node_type":"other","tokens":[{"end":32,"kind":"keyword","start":0,"text":"diag.arg(\"ty\","}]}
source_snippet:         diag.arg("ty", self.ty);
context_before:         let peeled_ty = self.ty.peel_refs();
context_after:         diag.arg("peeled_ty", peeled_ty);