So I am overriding a theme function by putting the contents in my template.php module, the problem is that it it throwing up loads of undefined index notices because there are lots of functions that are defined in the module. How can I define these in the template.php file and prevent the notices.

Note: I know i can turn them off

'uc_cart_block_content' => array(
      'variables' => array(
        'help_text' => NULL,
        'items' => NULL,
       'item_count' => NULL,
       'item_text' => NULL,
       'total' => NULL,
       'summary_links' => NULL,
       'collapsed' => TRUE,
          ),
      'file' => 'uc_cart.theme.inc',
    ),