pub fn sync_blocks<Block: BlockT, C, BE>(
    client: &C,
    substrate_backend: &BE,
    overrides: Arc<OverrideHandle<Block>>,
    frontier_backend: &Backend<Block>,
    limit: usize,
    sync_from: <Block::Header as HeaderT>::Number,
    strategy: SyncStrategy,
    sync_oracle: Arc<dyn SyncOracle + Send + Sync + 'static>,
    pubsub_notification_sinks: Arc<EthereumBlockNotificationSinks<EthereumBlockNotification<Block>>>
) -> Result<bool, String>
where C: ProvideRuntimeApi<Block> + HeaderBackend<Block> + StorageProvider<Block, BE>, C::Api: EthereumRuntimeRPCApi<Block>, BE: Backend<Block>,