Function big_blocks_stream 

pub(crate) fn big_blocks_stream(
    num_big_blocks: u64,
    target_gas: u64,
    block_stream: impl Stream<Item = Result<Option<(AnyRpcBlock, Option<BlockAccessList>)>>> + Unpin,
    initial_state: Option<BigBlocksInitialState>,
) -> impl Stream<Item = Result<BigBlockData<ExecutionData>>>

Produces a stream of big block payloads given a stream of regular blocks.