Perhaps this can be of use...

http://stackoverflow.com/questions/2289183/why-is-javas-abstractlists-removerange-method-protected

Then i get 

Then show what you tried to do...

don't have it here but if i recall it was something like

wData.companies = data.companies.subSet(5, data.companies.size()-1);

Anyway, i just loop over it now and then add items to a arrayList.

In ArrayList removeRange has protected scope which means it is not visible to you.

I suspect that in the statement
wData.companies.removeRange(5, wData.companies.size()-1);

companies is not an ArrayList but has been created from another class that inherits from ArrayList.

ArrayList<String> list = new ArrayList<String>();
list.addAll(Arrays.asList(new String[] { "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l" }));
println(list);
list.subList(5, 8).clear();
println(list);
exit();

To take a range of a list, indeed iteration can be better, as the result of subList() is actually tied to the original list.