a4aGr show method fails to find slot NA

[iagomosqueira]

The object output by example('a4aGr') brings an error when visualized using show(FLComp)

> show(vbObj)
An object of class "a4aGr"

Name:
Description:
Distr :  norm
Error in slot(X, slots[1]) :
  no slot of name "NA" for this object of class "a4aGr"
13: (function ()
    traceback(2))() at SClasses.R#293
12: slot(X, slots[1]) at FLComp.R#178
11: do.call(FUN, list(slot(X, slots[1]), ...)) at FLComp.R#178
10: is(do.call(FUN, list(slot(X, slots[1]), ...)), "FLArray") at FLComp.R#178
9: .local(X, FUN, ...)
8: qapply(obj, dim) at genericMethods.R#1068
7: qapply(obj, dim) at FLComp.R#426
6: dims(object) at genericMethods.R#902
5: dims(object) at FLComp.R#33
4: summary(object)
3: summary(object) at FLComp.R#57
2: (new("standardGeneric", .Data = function (object)
   standardGeneric("show"), generic = "show", package = "methods",
    ...
1: (new("standardGeneric", .Data = function (object)
   standardGeneric("show"), generic = "show", package = "methods",
    ../