private function fetchParameterExpansionSymbol($variable_name, $type)
    {
        $class = new \ReflectionClass($this);
        $symbol = $class->getConstant('SYMBOL_'.strtoupper($type));
        $pos = strpos($variable_name, $symbol);

        $check_empty = substr($variable_name, ($pos - 1), 1) === ":";

        if ($check_empty) {
            $symbol = sprintf(":%s", $symbol);
        }

        return array($symbol, $check_empty);
    }