Another method I will mention is using a paid service. Using these online paid tools may bring your more detailed information on the email addresses gathered with quality data. One example of this would be a site like CoCoFinder They have both free and paid services. People would use services like cocofinder to perhaps dig out more information on their customers, who purchases, their buying habits etc. - Source: dev.to / over 1 year ago

So if you don't know how to write unit tests, or how to use a mocking framework like https://easymock.org/ then you'll probably not find this principle very useful at all. That's okay. Just keep a note of it in the back of your mind, and then spend a few months writing unit tests for your code. At sound point, you'll find writing unit tests pretty painful, and that's probably where you'll discover mocking. Spend... Source: almost 2 years ago