Can't find conditional check in gatling 2.3.1

Hi,
I’m not sure if I got it right but according to the docs there should be a checkIf method available yet I can’t see it in the request builder.
I’m using IDEA and maven to build and run from Gatling archetype and maybe I messed up something after the update.
My pom.xml file has the following properties:

<properties>
   <maven.compiler.source>1.8</maven.compiler.source>
   <maven.compiler.target>1.8</maven.compiler.target>
   <scala.version>2.12.6</scala.version>
   <encoding>${encoding}</encoding>

   <gatling.version>2.3.1</gatling.version>

   <scala-maven-plugin.version>3.2.2</scala-maven-plugin.version>
</properties>

Just to be sure I downloaded pure gatling from the project page and copied the scala file, but the compilation crashed so I guess it’s just missing?

Would be grateful for any help.
Best regards,
Matt

checkIf_notfound_2018-08-07_14-15-30.png

Please have a lot at the documentation for the valid first parameter types: https://gatling.io/docs/2.3/http/http_check/?highlight=checkif#conditional-checking

Thanks - I was using it wrong and looking for it in the wrong class! lol: simple example

.check(checkIf(session => session.contains("9"))(css("meta[content*='.4']").exists))

BTW is there an option to apply css selector to session in the above example?

Best regards,
Matt