'Create an error-logger based on this logger, which does not contain the
given bad observer.
@param observer: The observer which previously had an error.
@type observer: L{ILogObserver}
@return: L{None}'

def _errorLoggerForObserver(self, observer):

    errorPublisher = LogPublisher(*[obs for obs in self._observers if (obs is not observer)])
    return Logger(observer=errorPublisher)
