Convert subpage & subitem to a integer

    * if page == 1, then return 0, since the item count is the true # of items
    * if page == 2, then return, page-1 * items_per_page, since we are
      returning the # of items on a full page.

    Args:
        * None

    Returns:
        * Integer - Which represents the number of items up to the page.

def sub_pi_to_number(self, subpage=1, subitem=1):
        """
    Convert subpage & subitem to a integer

    * if page == 1, then return 0, since the item count is the true # of items
    * if page == 2, then return, page-1 * items_per_page, since we are
      returning the # of items on a full page.

    Args:
        * None

    Returns:
        * Integer - Which represents the number of items up to the page.
        """
        if subitem == None:
            subitem = 0

        if subpage == None:
            return 0
        else:
            if subpage > 1:
                return ((subpage - 1) * self.subpage_items) + subitem
            else:
                return 0 + subitem