CA Civ Proc Code Section 2035.010

(a)

One who expects to be a party or expects a successor in interest to be a party to any action that may be cognizable in any court of the State of California, whether as a plaintiff, or as a defendant, or in any other capacity, may obtain discovery within the scope delimited by Chapters 2 (commencing with Section 2017.010) and 3 (commencing with Section 2017.710), and subject to the restrictions set forth in Chapter 5 (commencing with Section 2019.010), for the purpose of perpetuating that person’s own testimony or that of another natural person or organization, or of preserving evidence for use in the event an action is subsequently filed.

(b)

One shall not employ the procedures of this chapter for the purpose either of ascertaining the possible existence of a cause of action or a defense to it, or of identifying those who might be made parties to an action not yet filed.