Firefox view source window

I have been doing web development for a long time, but today I accidentally noticed this feature of Mozilla Firefox: if you open the view source window, you can update it just like a regular page window.

Those. it used to be like this:

• code change;
• switch to the browser window;
• Ctrl + R;
• visual study of the result;
• view-source (Ctrl + U) and a detailed study of the result;

Today I accidentally switched not to the browser window, but to the view-source window and updated it, the page has refreshed.

Related Links:
Expansion of a convenient view of the source code of the page: addons.mozilla.org/en-US/firefox/addon/655
A set of extensions for the web developer: www.habrahabr.ru/blog/webdev/9431.html
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PS I use extensions of course, but I haven’t refused the habit of pressing Ctrl + U. Similarly, out of habit, I considered that the window being opened is static and it only remains to close it after studying; turns out to be wrong.