California Code, Code of Civil Procedure - CCP § 2035.050

(a) If the court determines that all or part of the discovery requested under this chapter may prevent a failure or delay of justice, it shall make an order authorizing that discovery.In determining whether to authorize discovery by a petitioner who expects a successor in interest to be a party to an action, the court shall consider, in addition to other appropriate factors, whether the requested discovery could be conducted by the petitioner's successor in interest, instead of by the petitioner.

(b) The order shall identify any witness whose deposition may be taken, and any documents, things, or places that may be inspected, and any person whose physical or mental condition may be examined.

(c) Any authorized depositions, inspections, and physical or mental examinations shall then be conducted in accordance with the provisions of this title relating to those methods of discovery in actions that have been filed.