NewBlockMonitor creates an BlockMonitor with the provided HeaderGetter, Publisher, and BlockRecorder.

NewRPCBlockMonitor creates a BlockMonitor using an ehtclient to the specified rpcURL for a HeaderGetter.

BlockMonitor watches a HeaderGetter (probably an ethclient)for new blocks, publishing new blocks to a Publisher.

MiniBlock is a subset of the Ethereum block header that has the subset of fields we need to monitor for events.

BlockRecorder keeps track of the last recorded block, primarily so that the block monitor can resume where it left off in the event that it restarts.

HeaderGetter returns block headers by hash or number.