Magento2: how to access DwollaSwagger class inside…

Hi … I am attempting to incorporate dwolla repayment entrance in my job, I have posted DwollaSwagger data( 3rd party collection) inside ‘lib/internal/dwolla/’ folder, I am attempting to call DwollaSwagger.php course from my Block however obtaining mistakes similar to this

main.CRITICAL: Mistake: Course ‘DemoDwollaBlockDemoDwollaSwagger’ not discovered in app/code/Demo/ Dwolla/Block/Demo/ Customer.php:30

My block course: