'If the error is a L{util.DirtyReactorAggregateError}, instead of
reporting it as a normal error, throw a warning.'

def addError(self, test, error):

    if (isinstance(error, Failure) and error.check(util.DirtyReactorAggregateError)):
        warnings.warn(error.getErrorMessage())
    else:
        self._originalReporter.addError(test, error)
