@Override
  public long computeExcessBlobGas(
      final long parentExcessBlobGas,
      final long parentBlobGasUsed,
      final long parentBaseFeePerGas) {
    final long currentExcessBlobGas = parentExcessBlobGas + parentBlobGasUsed;
    if (currentExcessBlobGas < targetBlobGasPerBlock) {
      return 0L;
    }
    return currentExcessBlobGas - targetBlobGasPerBlock;
  }
Using Cancun mainnet default of 6 blobs for maxBlobsPerBlock: getBlobGasPerBlob() * 6 blobs =
131072 * 6 = 786432 = 0xC0000
ethereum/core/src/main/java/org/hyperledger/besu/ethereum/mainnet/CancunTargetingGasLimitCalculator.java