'Add a new observer.
@type other: Provider of L{ILogObserver}
@param other: A callable object that will be called with each new log
message (a dict).'

def addObserver(self, other):

    wrapped = LegacyLogObserverWrapper(other)
    self._legacyObservers.append(wrapped)
    self._observerPublisher.addObserver(wrapped)
