Unable to use Swift function that returns String on Java side

[dieter115]

I'm using jextract-swift to create Java Classes for the Sources/MySwiftLibrary/SwiftKitSamleApp for the sample SwiftKitSampleApp.

I created the following function just to test something in HelloJava2Swift.swift

public func retrieveToken() -> String {
  return "test"
}

But when I try to do the following in MySwiftLibraryTest.java

@Test
    void call_retrieveToken() {
        MySwiftLibrary.retrieveToken();
        assertNotNull(MySwiftLibrary.retrieveToken$address());
    }

It gives the following error

I'm probably forgetting something important.