mDataSource = dont_QueryInterface(aDataSource);
mDataSource = aDataSource;
RDFContentSinkImpl::SetDataSource(nsIRDFDataSource* aDataSource){    NS_PRECONDITION(aDataSource != nsnull, "SetDataSource null ptr");    mDataSource = dont_QueryInterface(aDataSource);    NS_ASSERTION(mDataSource != nsnull,"Couldn't QI RDF DataSource");    return NS_OK;}