Trust for self-employed individuals and others.

No trust created under a retirement plan for which provision has been made under the laws of the United States exempting such trust from federal income tax shall be deemed to be invalid as violating any existing laws against perpetuities or suspension of the power of alienation of title to property or the accumulation of income; but such a trust may continue for such time as may be necessary to accomplish the purposes for which it may be created, may be permitted to accumulate the income until such time as such income shall become distributable to the beneficiary or beneficiaries under the terms of the trust and may according to its terms be made irrevocable and the interests of its beneficiary or beneficiaries therein may be made nontransferable by assignment or otherwise.