Function fc_rpc::frontier_backend_client::native_block_id

pub async fn native_block_id<B, C>(
    client: &C,
    backend: &(dyn BackendReader<B> + Send + Sync),
    number: Option<BlockNumber>
) -> RpcResult<Option<BlockId<B>>>where
    B: BlockT,
    C: HeaderBackend<B> + 'static,