NS_PRECONDITION(aEnv != nsnull, "null ptr"); if (! aEnv) return NS_ERROR_NULL_POINTER;  NS_PRECONDITION(aTable != nsnull, "null ptr"); if (! aTable) return NS_ERROR_NULL_POINTER;  mEnv = aEnv; mEnv->AddStrongRef(mEnv);  mTable = aTable; mTable->AddStrongRef(mEnv);  mColumn = aColumn;  mdb_err err; err = mTable->GetTableRowCursor(mEnv, -1, &mCursor); if (err != 0) return NS_ERROR_FAILURE;  if (gRefCnt++ == 0) { nsresult rv; rv = nsServiceManager::GetService(kRDFServiceCID, nsCOMTypeInfo<nsIRDFService>::GetIID(), (nsISupports**) &gRDFService); if (NS_FAILED(rv)) return rv; }  return NS_OK;
return(NS_OK);
nsMdbTableEnumerator::Init(nsIMdbEnv* aEnv,                           nsIMdbTable* aTable,                           mdb_column aColumn){  NS_PRECONDITION(aEnv != nsnull, "null ptr");  if (! aEnv)    return NS_ERROR_NULL_POINTER;  NS_PRECONDITION(aTable != nsnull, "null ptr");  if (! aTable)    return NS_ERROR_NULL_POINTER;  mEnv = aEnv;  mEnv->AddStrongRef(mEnv);  mTable = aTable;  mTable->AddStrongRef(mEnv);  mColumn = aColumn;  mdb_err err;  err = mTable->GetTableRowCursor(mEnv, -1, &mCursor);  if (err != 0) return NS_ERROR_FAILURE;  if (gRefCnt++ == 0) {    nsresult rv;    rv = nsServiceManager::GetService(kRDFServiceCID,                                      nsCOMTypeInfo<nsIRDFService>::GetIID(),                                      (nsISupports**) &gRDFService);    if (NS_FAILED(rv)) return rv;  }  return NS_OK;}