@Override
  public Optional<PoWSolverInputs> getWorkDefinition() {
    return currentRunningMiner.flatMap(PoWBlockMiner::getWorkDefinition);
  }
Responsible for determining when a block mining operation should be started/stopped, then
creating an appropriate miner and starting it running in a thread.
ethereum/blockcreation/src/main/java/org/hyperledger/besu/ethereum/blockcreation/PoWMiningCoordinator.java