NS_ASSERTION(observer != nsnull, "null ptr"); if (! observer)
NS_PRECONDITION(aObserver != nsnull, "null ptr"); if (! aObserver)
InMemoryDataSource::RemoveObserver(nsIRDFObserver* observer){    NS_ASSERTION(observer != nsnull, "null ptr");    if (! observer)        return NS_ERROR_NULL_POINTER;    NS_AUTOLOCK(mLock);    if (! mObservers)        return NS_OK;    mObservers->RemoveElement(observer);    return NS_OK;}