private function fixControlStructure(Tokens $tokens, $index)
    {
        // Ensure a single whitespace
        if (!$tokens[$index - 1]->isWhitespace() || $tokens[$index - 1]->isWhitespace($this->singleLineWhitespaceOptions)) {
            $tokens->ensureWhitespaceAtIndex($index - 1, 1, ' ');
        }

    }