public function find_by_id($id)
 {
     if (absint($id) === 0) {
         return $this->get_free_payment_term();
     }
     return AWPCP_Fee::find_by_id($id);
 }
 private function ajax_delete($id)
 {
     $errors = array();
     if (is_null(AWPCP_Fee::find_by_id($id))) {
         $message = _x("The specified Credit Plan doesn't exists.", 'credit plans ajax', 'AWPCP');
         $response = array('status' => 'error', 'message' => $message);
     } else {
         $this->get_table();
         $columns = count($this->table->get_columns());
         ob_start();
         include AWPCP_DIR . '/admin/templates/admin-panel-fees-delete-form.tpl.php';
         $html = ob_get_contents();
         ob_end_clean();
         $response = array('status' => 'success', 'html' => $html);
     }
     return $response;
 }