How does \Magento\Weee\Model\Total\Quote\Weee::process() work?

Context: How does \Magento\Weee\Model\Total\Quote\Weee::collect() work?

Details: How does \Magento\Weee\Model\Total\Quote\Weee::processTotalAmount() work?

Details: How does \Magento\Weee\Helper\Data::setApplied() work?