What is the test for dismissing an action for lack of prosecution?

In Weeks v. Roberts (1968) 68 Cal.2d 802, 807-808, 69 Cal.Rptr. 305, 442 P.2d 361, we held that where a plaintiff moves to specially set a case for trial in order to avoid dismissal under the five-year rule (Code Civ.Proc., 583, subd. (b)) ¹ and the "court feels impelled to dismiss an action less than five years after its filing for want of prosecution, it should do so and accept review on that basis. It should not exercise its discretion to dismiss on the basis of inconvenience

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