Leafo\ScssPhp\Compiler::libJoin PHP Method

    protected function libJoin($args)
    {
        list($list1, $list2, $sep) = $args;
        $list1 = $this->coerceList($list1, ' ');
        $list2 = $this->coerceList($list2, ' ');
        $sep = $this->listSeparatorForJoin($list1, $sep);
        return [Type::T_LIST, $sep, array_merge($list1[2], $list2[2])];
    }