private NatMethod retrieveNatMethod(final Optional<NatManager> natManager) {
    return natManager.map(NatManager::getNatMethod).orElse(NatMethod.NONE);
  }
Retrieve the current NatMethod.

@param natManager The natManager wrapped in a {@link Optional}.
@return the current NatMethod.
nat/src/main/java/org/hyperledger/besu/nat/NatService.java