When is the 'require' necessary when using a ruby gem?
<p>I noticed for some gems you must include it in the file where you want to use it like this <code>require 'a_gem'</code>, but this is not always the case.</p>

<p>I am going to compose a gem by myself. What should I do if I do not want to add the <code>require 'my_gem'</code> to the .rb file when using it?</p>