@Override
    public Optional<PARENT> getParent() {
        @SuppressWarnings("unchecked")
        final Optional<PARENT> parent = (Optional<PARENT>) super.getParent();
        return parent;
    }
@author          Emil Forslund
@param <PARENT>  the parent interface
runtime-parent/runtime-config/src/main/java/com/speedment/runtime/config/internal/AbstractChildDocument.java