Thank you very much for hint, Sebastian. I had to modify it a little. Here is the method, that worked for me finally :-)
class EnumDslJvmModelInferrer extends AbstractModelInferrer {
@Inject extension JvmTypesBuilder
def dispatch void infer(EnumModel element, IJvmDeclaredTypeAcceptor acceptor, boolean isPreIndexingPhase) {
element.pckg.enums.forEach[ myEnum |
acceptor.accept(myEnum.toEnumerationType(element.pckg.name+"."+myEnum.name)[]).initializeLater[
myEnum.items.forEach [ literal |
it.members += myEnum.toEnumerationLiteral(literal)
]
]
]
}
}