// x = names and components interleaving.
// or just components.
// or just names.
// also, first element can be index of tab to open at start
// also, SUPER short demo syntax: jtabs(3)
// also, you can pass a Collection containing the elements
static JTabbedPane fillJTabs(final JTabbedPane tabs, O... x) {
  if (tabs == null) null;
  clearTabs(tabs);
  addTabs(tabs, x);
  ret tabs;
}