EDIT

    /**

     * Returns the boolean value indicating whether <i>this</i> taxon is a invalid designation

     * for at least one other taxon.

     */

    // TODO cache as for #hasTaxonomicChildren

    @Transient

    public boolean isInvalidDesignation(){

        return computeInvalidDesignationRelations() > 0;

    }

    /**

     * Counts the number of invalid designation relationships where this taxon represents the

     * invalid designation for another taxon.

     * @return

     */

    private int computeInvalidDesignationRelations(){

        int count = 0;

        for (TaxonRelationship rel: this.getRelationsFromThisTaxon()){

            if (rel.getType().isInvalidDesignation()){

                count++;

            }

        }

        return count;

    }

    /**

     * @see     #getSynonymsGroups()

     */

    @Transient

    public List<Taxon> getInvalidDesignations(){

        List<Taxon> result = new ArrayList<>();

        for (TaxonRelationship rel : this.getRelationsToThisTaxon()){

            if (rel.getType().isInvalidDesignation()){

                result.add(rel.getFromTaxon());

            }

        }

        sortBySimpleTitleCacheComparator(result);

        return result;

    }