Sometimes when I'm editing posts which need preformatting (mainly code preformats), If I click on the {} icon on editing tools tabs:

I can't achieve the effect I want, instead the texts appears to be just indented and not preformatted as a block. I have noticed this frequently with lengthy paragraphs which need to be formatted as code. Inline preformatting works fine with `` .

How can I create a preformatted block span of texts during editing?