The declared package does not match the expected package XTEND

Question

I have written xtend code that generates java classes, but in the generated java classes, there is an error in the package. Error: "The declared package "systemunit.abstractsystemunit" does not match the expected package "systemunit.abstractsystemunit""

private static def dispatch void generateFiles(SystemUnit systemUnit, IFileSystemAccess fsa) {
    println("generateFiles(SystemUnit systemUnit): " + systemUnit)


    val String packageName=StatesMLCodeGeneratorStrings.getSystemUnitPackageName(systemUnit)
    val String className=StatesMLCodeGeneratorStrings.getSystemUnitClassName(systemUnit)

    fsa.generateFile('''«packageName»/«className».java''', '''
        // Generating code for «systemUnit.name»
        package «packageName»;

        public class «className»{

        }
    ''')
}

Does someone knows that is the problem and how to resolve in XTend ?

Thanks in advnace !