import(methods) import(graphics) ## instead of just ## importFrom("graphics", plot) # because we want to define methods on it ## *Still* do not want warning from this ## as "mgcv": this loads Matrix, but does not attach it ==> Matrix methods "semi-visible" importFrom(Matrix, t,mean,colMeans,colSums) exportClasses("classA", "classApp") # mother and sub-class R/pkgA.R exportMethods("plot") export(nil) export(search)# --> "conflict message"