'Add a new page with the name given in page_name.'

def add_page(self, page_name):

    if (not page_name):
        raise InvalidNameError(("Invalid    TabPage    name:    '%s'" % page_name))
    if (page_name in self.pages):
        raise AlreadyExistsError(("TabPage    named    '%s'    already    exists" % page_name))
    self.pages[page_name] = self.page_class(self.pages_frame)
    self._pages_order.append(page_name)
    self._tab_set.add_tab(page_name)
    if (len(self.pages) == 1):
        self._default_page = page_name
        self.change_page(page_name)
