if (mReadCount) { NS_WARNING("Writing to InMemoryDataSource during read\n"); return NS_RDF_ASSERTION_REJECTED; }
InMemoryDataSource::Unassert(nsIRDFResource* aSource,                             nsIRDFResource* aProperty,                             nsIRDFNode* aTarget){    NS_PRECONDITION(aSource != nsnull, "null ptr");    if (! aSource)        return NS_ERROR_NULL_POINTER;    NS_PRECONDITION(aProperty != nsnull, "null ptr");    if (! aProperty)        return NS_ERROR_NULL_POINTER;    NS_PRECONDITION(aTarget != nsnull, "null ptr");    if (! aTarget)        return NS_ERROR_NULL_POINTER;    nsresult rv;    rv = LockedUnassert(aSource, aProperty, aTarget);    if (NS_FAILED(rv)) return rv;    // Notify the world    for (PRInt32 i = PRInt32(mNumObservers) - 1; mPropagateChanges && i >= 0; --i) {        nsIRDFObserver* obs = mObservers[i];        // XXX this should never happen, but it does, and we can't figure out why.        NS_ASSERTION(obs, "observer array corrupted!");        if (! obs)          continue;        obs->OnUnassert(this, aSource, aProperty, aTarget);        // XXX ignore return value?    }    return NS_RDF_ASSERTION_ACCEPTED;}