@Override
  public PayloadIdentifier preparePayload(
      final BlockHeader parentHeader,
      final Long timestamp,
      final Bytes32 prevRandao,
      final Address feeRecipient,
      final Optional<List<Withdrawal>> withdrawals,
      final Optional<Bytes32> parentBeaconBlockRoot) {
    return mergeCoordinator.preparePayload(
        parentHeader, timestamp, prevRandao, feeRecipient, withdrawals, parentBeaconBlockRoot);
  }
Gets merge coordinator.

@return the merge coordinator
consensus/merge/src/main/java/org/hyperledger/besu/consensus/merge/blockcreation/TransitionCoordinator.java