how to take snapshot of screen programmatically?

I want to take screenshot of screen programatically.I also downloaded android-screenshot-library, but i am not understanding how to use it. Please help me.

Thanks

How do I take a snapshot of my screen?

Press the Power and Volume down buttons at the same time. If that doesn't work, press and hold the Power button for a few seconds. Then tap Screenshot.

Can we automate taking screenshots?

Automated Screenshot testing will help you capture screenshots in bulk through different desktops and mobile devices running on various OS in a single go! It is facilitated by instrumented UI test cases to help you realize how seamlessly your web app renders through different screen sizes using different browsers.

Follow this guide: Developer guide for android-screenshot-library.

Also read this: How to capture the android device screen content? may be become helpful to you.