WordPress: redirect non-www to www .htaccess

Hi, this is just a braindump, but I made it public so it can help someone else.
If you are using WordPress and want to force your site respond to www instead of non-www, copy and paste this in your .htaccess:

RewriteEngine On
RewriteCond %{HTTP_HOST} !^(nic|www)\. [NC]
RewriteRule ^(.*) https://www.%{HTTP_HOST}/$1 [QSA,L,R=301]

Observe that I’m using https, so if you need only http, erase de ‘s’