Classes not exposed?

[arne-fuchs]

Hello I am trying to implement a code completion plugin which depends on this solidity plugin.
I have structs like this:

if (functionOrVariable instanceof SolFunctionDefinitionImpl func){
    if (func.getReturns() != null){
        text = func.getReturns().getText();
    }
}

If I run the plugin standalone the classes are not being found.
But if I run gradle tests the classes are available (which I do not understand).
The error is as follwed:
java.lang.NoClassDefFoundError: me/serce/solidity/lang/psi/impl/SolStateVariableDeclarationImpl
My dependencies are defined as followed:
platformPlugins = JavaScript, me.serce.solidity:2.4.3, java

I am able to work with the Javascript Classes but not with the solidity classes.
Are they not exposed?