Use of latticeExtra without import

[iagomosqueira]

plot(a4aFitResiduals) tries to use latticeExtra if available, but R CMD check complains about the method not being imported

* checking dependencies in R code ... WARNING
'::' or ':::' import not declared from: ‘latticeExtra’

In fact, latticeExtra is not even suggested in DESCRIPTION. Need to see how best to solve it.