williams' influence in the highest courts was sustained and significant. one notable example is in "r v shivpuri" [1986] a.c. 1, where the defendant imported harmless vegetable material akin to snuff believing he was importing drugs. the house of lords held: "it was immaterial that the appellant was unsure of the exact nature of the substance in his possession in that in any event he believed that he was dealing with either heroin or cannabis the importation of which was prohibited." lord bridge of harwich stated: