Magento 2.2 error when di:compile is run

Question

Error:

Errors during compilation: Tdsoft\Pdfbuilder\Model\ResourceModel\Invoice\Grid\Collection Incompatible argument type: Required type: \Magento\Framework\DB\Adapter\AdapterInterface. Actual type: \Tdsoft\Pdfbuilder\Model\ResourceModel\Invoice\Grid\connection; File: /home/sertarul/public_html/app/code/Tdsoft/Pdfbuilder/Model/ResourceModel/Invoice/Grid/Collection.php

Total Errors Count: 1

Collection.php content:

 public function __construct(
    \Magento\Framework\Data\Collection\EntityFactoryInterface $entityFactory,
    \Psr\Log\LoggerInterface $logger,
    \Magento\Framework\Data\Collection\Db\FetchStrategyInterface $fetchStrategy,
    \Magento\Framework\Event\ManagerInterface $eventManager,
    $mainTable,
    $eventPrefix,
    $eventObject,
    $resourceModel,
    $model = 'Magento\Framework\View\Element\UiComponent\DataProvider\Document',
    $connection = null,
    \Magento\Framework\Model\ResourceModel\Db\AbstractDb $resource = null 
)
{
    parent::__construct($entityFactory, $logger, $fetchStrategy, $eventManager, $connection, $resource);
    $this->_eventPrefix = $eventPrefix;
    $this->_eventObject = $eventObject;
    $this->_init($model, $resourceModel);
    $this->setMainTable($mainTable);
}

Answer 1

Please $connection use as below in the Collection.php

 public function __construct(
    ...
    \Magento\Framework\DB\Adapter\AdapterInterface  $connection = null,
    ...
) {
    ...
}

Again do the compile

Reference link:-https://goo.gl/ux9GnG

Answer 2

I have changed the line

 $connection = null,

with

\Magento\Framework\DB\Adapter\AdapterInterface  $connection = null,

Now is working!