if ($parameter->getUnionType()->isEmpty()) {
                $warning_closures[$i] = static function () use ($code_base, $parameter, $method, $i, &$inferred_types): void {
                    $suggestion = self::suggestionFromUnionType($inferred_types[$i] ?? null);
                    self::emitIssueAndSuggestion(
                        $code_base,