Cambridge Law Interview Pre-reading

Hi :) Do all cambridge law interviews assign pre-reading materials? In my invitation letter there is no mentioning of any pre-reading materials needed (and in the guidance doc they send me it is mentioned that if pre-reading is required it would be mentioned in the invitation letter). But I've always heard about needing to read assigned materials before oxbridge law interviews. So is it something that varies across college? Is it normal to not have pre-reading materials for cambridge law interviews?