I think that you should look class `Magento\Backend\Block\Widget\Form\Element\Dependence`. You can create your own block inherited from this class and rewrite it how you want. In your code replaces block call:

    $this->getLayout()->createBlock(
        'Magento\Backend\Block\Widget\Form\Element\Dependence'
    )

to:   

    this->getLayout()->createBlock(
        'Siarhey\Test\Block\Widget\Form\Element\Dependence'
    )

Create block `Siarhey\Test\Block\Widget\Form\Element\Dependence` and you can implement in it your logic of verification.

It is only advice. I hope that it helps you.