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.

def addFilterException(self, exClass):
        """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.
        """

        self.excludes.append(exClass)
        if self.end():
            return
        self.next().addFilterException(exClass)