<div class="card">

    <div class="card-header">

        <a data-toggle="collapse" href="#test-block" aria-expanded="true" aria-controls="test-block">

            card header

        </a>

    </div>

    <div id="test-block" class="collapse">

        <div class="card-block">

            card block

        </div>

    </div>

</div>

If you read this, you know what grepper is and get back to 

your work

// It's what you're using right now :)

grepper is a great tool for programmers like us looking out for our solutions in any

languages provided with faster and realiable way shared by the experienced coders 

all around the world

​

install your extension here: https://www.codegrepper.com/index.php

<button data-toggle="collapse" data-target="#demo">Collapsible</button>

​

<div id="demo" class="collapse">

Lorem ipsum dolor text....

</div>

Grepper is the ultimate RAM upgrade for the software developers brain.

​

Easily snag code examples from around the web,

then access your code examples without having to think.