In Kaplan's Fruit & Produce Co. v. Superior Court (1979) 26 Cal.3d 60, an agricultural employer sought to enjoin what it claimed to be mass picketing on the part of the UFW, blocking ingress and egress to Kaplan's wholesale facility in Los Angeles. The trial court found that such mass picketing had occurred, but ruled that in the absence of violence or threat of violence it had no jurisdiction to grant injunctive relief. The Supreme Court disagreed, and held "that the ALRA does not divest the superior courts of jurisdiction, in a suit by private parties, to enjoin obstructions to access." (26 Cal.3d at p. 75.) In reaching that conclusion, the Supreme Court took note of its prior holding in Belridge Farms v. Agricultural Labor Relations Bd. (1978) 21 Cal.3d 551, 558, that the "exclusive method" language of section 1160.9 "simply constitutes a codification of existing federal law." "Accordingly," the court continued, "in defining the scope of preemption under section 1160.9, we adhere to the Legislature's directive in Labor Code section 1148 to 'follow applicable precedents of the National Labor Relations Act, as amended.' As explained in People v. Medrano (1978) 78 Cal.App.3d 198, 205 . . . : 'In designating the NLRA precedents as guideposts, the ALRA apparently incorporates into California law the general features of the federal preemption doctrine.' We therefore look to cases interpreting the NLRA as a guide to the determination of whether the ALRA preempts the power of superior courts to enjoin obstructions to access in a private suit." (26 Cal.3d at pp. 67-68.) The court then proceeded to examine relevant federal precedents. It observed that while decisions of the United States Supreme Court had established as a general principle that the NLRB has exclusive jurisdiction over conduct which arguably involves practices either protected or prohibited under the NLRA ( San Diego Unions v. Garmon (1959) 359 U.S. 236), an exception to the general rule of preemption allows for the power of local courts and agencies to adjudicate matters of particular local concern; and that the federal decisions "specifically acknowledge that local courts and agencies retain jurisdiction over private actions to enjoin obstructions to access." (26 Cal.3d at p. 68.) The court noted its own prior declaration in Sears, Roebuck & Co. v. San Diego County Dist. Council of Carpenters (1976) 17 Cal.3d 893, reversed on other grounds, 436 U.S. 180, that "'despite the Garmon rule, power was reserved to the states to prevent mass picketing, violence, threats of violence and obstructions to ingress and egress which threatened public health and safety.'" (26 Cal.3d at p. 69, fn. 5.)