Have a test class like and import it into foreman:
class base ( $test = true, $othertest = false ) {

}

Add a parameter:
class base ( $test = true, $othertest = false, $otherothertest = true ) {

}

Run an import:
[root@s02 ~]# cd /usr/share/foreman
[root@s02 foreman]# RAILS_ENV=production /usr/bin/ruby193-rake puppet:import:puppet_classes
/opt/rh/ruby193/root/usr/share/rubygems/rubygems/custom_require.rb:36:in `require': iconv will be deprecated in the future, use String#encode instead.
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But go into the UI and import and get:
development Update: base