{"ast_node_type":"other","tokens":[{"end":69,"kind":"keyword","start":0,"text":"ecx.dcx().create_err(errors::FormatUnusedArg"}]}
        ecx.dcx().create_err(errors::FormatUnusedArg { span, named })
    let mut diag = if let &[(span, named)] = &unused[..] {
    } else {