/**
	 * loads and returns the cbpaidPaymentItem's of this cbPaymentBasket
	 * they are cached into $this->_paymentItems as array of cbpaidPaymentItem
	 *
	 * @return cbpaidPaymentTotalizer[]
	 */
	public function & loadPaymentTotalizers() {
		global $_CB_database;

		if ( $this->_paymentTotalizers === null ) {
			$sampleItem					=	new cbpaidPaymentTotalizer( $_CB_database );
			$this->_paymentTotalizers	=	$sampleItem->loadThisMatchingList( array( 'payment_basket_id' => (int) $this->id ), array( 'ordering' => 'ASC' ) );

			// Now also link back to basket, as it is needed to be able to display totalizers correctly:
			foreach ( array_keys( $this->_paymentTotalizers ) as $k ) {
				$this->_paymentTotalizers[$k]->setPaymentBasketObject( $this );
			}
		}
		return $this->_paymentTotalizers;
	}
 /**
  * Renders a $variable for an $output
  *
  * @param  mixed   $variable
  * @param  string  $output
  * @param  boolean $rounded
  * @return string|null
  */
 public function renderColumn($variable, $output = 'html', $rounded = false)
 {
     if (!in_array($variable, array('rate', 'first_rate', 'validity_period', 'description')) && (is_callable('property_exists') ? property_exists($this, $variable) : property_exists($this, $variable)) && $this->{$variable} == 0) {
         return null;
     }
     return parent::renderColumn($variable, $output, $rounded);
 }