EDIT

import java.util.Optional;

import eu.etaxonomy.cdm.model.name.TypeDesignationStatusBase;

    public BeanItemContainer<TypeDesignationStatusBase> buildTypeDesignationStatusBaseItemContainer(List<UUID> termsUuids,

            Optional<Boolean> withHasDesignationSource) {

        clearSession();

        List<DefinedTermBase> terms = repo.getTermService().load(termsUuids, INIT_STRATEGY);

        BeanItemContainer<TypeDesignationStatusBase> termItemContainer = new BeanItemContainer<>(DefinedTermBase.class);

        termItemContainer.addAll(terms.stream()

                .filter(t -> t instanceof TypeDesignationStatusBase)

                .map(t -> (TypeDesignationStatusBase)t)

                .filter(tsb ->

                    !withHasDesignationSource.isPresent()

                    || withHasDesignationSource.get().equals(false)

                    || tsb.hasDesignationSource() == true

                )

                .collect(Collectors.toList())

        );

        return termItemContainer;

    }