Icon size classes like size-50 do not seem to work

Questions
1

Hi!
the custom font-size classes for icons do not seem to work… If I try this

<i class="f7-icons size-22">house</i>
<i class="f7-icons size-25">house</i>
<i class="f7-icons size-29">house</i>
<i class="f7-icons size-50">house</i>

there is no difference… all same and I also can’t find associated classes… Is there something additional to install to make this work?