/**
  * Filter the query by a related Factura object
  *
  * @param   Factura|PropelObjectCollection $factura  the related object to use as filter
  * @param     string $comparison Operator to use for the column comparison, defaults to Criteria::EQUAL
  *
  * @return                 PacientefacturacionQuery The current query, for fluid interface
  * @throws PropelException - if the provided filter is invalid.
  */
 public function filterByFactura($factura, $comparison = null)
 {
     if ($factura instanceof Factura) {
         return $this->addUsingAlias(PacientefacturacionPeer::IDPACIENTEFACTURACION, $factura->getIddatosfacturacion(), $comparison);
     } elseif ($factura instanceof PropelObjectCollection) {
         return $this->useFacturaQuery()->filterByPrimaryKeys($factura->getPrimaryKeys())->endUse();
     } else {
         throw new PropelException('filterByFactura() only accepts arguments of type Factura or PropelCollection');
     }
 }