@Test
  public void validateHeader_BlobGasDifferentFromCalculated_FailsValidation() {
    long target = cancunTargetingGasLimitCalculator.getTargetBlobGasPerBlock();

    // Create parent header
    final BlockHeaderTestFixture parentBuilder = new BlockHeaderTestFixture();
    parentBuilder.excessBlobGas(BlobGas.of(1L));
    parentBuilder.blobGasUsed(target);
    final BlockHeader parentHeader = parentBuilder.buildHeader();

    // Create block header with different excessBlobGas
    final BlockHeaderTestFixture headerBuilder = new BlockHeaderTestFixture();
    final BlockHeader header = headerBuilder.buildHeader();

    assertThat(cancunBlobGasValidationRule.validate(header, parentHeader)).isFalse();
  }
Cancun EIP-4844 - Tests that the header blob gas is different from the calculated blob gas and
fails validation.
ethereum/core/src/test/java/org/hyperledger/besu/ethereum/mainnet/headervalidationrules/BlobGasValidationRuleTest.java