CCP 2892     

Art. 2892.  Use of probate testimony in subsequent action

When a testament has been probated in accordance with law, the record of the substance of the testimony of any witness at the hearing, and the deposition of any witness taken under Article 2889, shall be admissible in evidence in any subsequent action in which it is sought to annul the testament, if at the time of trial thereof the witness has died, or for any other reason his testimony cannot be taken again either by subpoenaing him to appear at the trial, or by deposition.