As a clarification of existing law, unless a testamentary power of appointment expressly states that it is a general power of appointment or expressly authorizes the donee to exercise the power of appointment in favor of one or more of the donee’s creditors, the donee’s estate or the creditors of the donee’s estate, the power of appointment shall be construed as a special power of appointment, and the donee may not appoint in favor of the donee’s creditors, the donee’s estate or the creditors of the donee’s estate. For the purposes of this section, the term “testamentary power of appointment” shall mean a power to appoint property exercisable only at the death of the donee of the power, whether by the donee’s will or otherwise.