(a) An agreement may be made to create a lien upon property not yet acquired by the party agreeing to give the lien, or not yet in existence. In that case the lien agreed for attaches from the time when the party agreeing to give it acquires an interest in the thing, to the extent of such interest.
(b) For purposes of subdivision (a), an agreement by a beneficiary of an estate that is subject to administration, as provided in Division 7 (commencing with Section 7000) of the Probate Code, to create a lien upon real property in the estate that is undistributed at the time the agreement is entered into, shall create no lien upon the real property unless and until the real property is distributed to that beneficiary. Upon recordation of an order confirming the sale of the real property pursuant to Section 10313 of the Probate Code and the recording of a duly executed deed in accordance therewith, any expectancy of a lien in the real property under the agreement shall be extinguished.