@Override
  public long extCodeHashOperationGasCost() {
    throw new UnsupportedOperationException(
        "EXTCODEHASH not supported by " + getClass().getSimpleName());
  }
Returns the base gas cost for external code accesses.

@return the base gas cost for external code accesses
evm/src/main/java/org/hyperledger/besu/evm/gascalculator/FrontierGasCalculator.java