Function polkadot_node_subsystem::forward_events

pub async fn forward_events<P>(
    client: Arc<P>,
    handle: Handle
) -> impl Future<Output = ()>where
    P: BlockchainEvents<Block<Header<u32, BlakeTwo256>, OpaqueExtrinsic>>,

Glues together the Overseer and BlockchainEvents by forwarding import and finality notifications into the OverseerHandle.