code: def addFilterException(self, exClass):
          
  
          self.excludes.append(exClass)
          if self.end():
              return
          self.next().addFilterException(exClass)
docs: Add an exception filter to the error checking chain.
  
          @param exClass:    the exception to exclude, e.g.
          L{smartcard.sw.SWExceptions.WarningProcessingException} A filtered
          exception will not be raised when the sw1,sw2 conditions that
          would raise the excption are met.