public static final int SMB2_FLAGS_REPLAY_OPERATION = 0x20000000;

    private int command;
    private int flags;
    private int length, headerStart, wordCount, byteCount;

    private final byte[] signature = new byte[16];
    private Smb2SigningDigest digest = null;

    private final Configuration config;

    private int creditCharge;
    private int status;
    private int credit;

        // Check SMB1 signature
        if (protocolId == 0x424D53FF) { // 0xFF 'S' 'M' 'B'
            // SMB1
            if (structureSize < 32 || structureSize > 65535) {
                failedValidations.incrementAndGet();
                throw new SmbException("Invalid SMB1 header size: " + structureSize);
            }
        }
        // Check SMB2/3 signature

    }

    @Override
    public @Nullable Object[] toArray() {
      return standardToArray();
    }

    @Override
    @SuppressWarnings("nullness") // bug in our checker's handling of toArray signatures
    public <T extends @Nullable Object> T[] toArray(T[] array) {
      return standardToArray(array);
    }

    @Override
    public String toString() {
      return standardToString();
    }
  }

  @Override
  public boolean put(@ParametricNullness K key, @ParametricNullness V value) {
    return super.put(key, value);
  }

  /**
   * {@inheritDoc}
   *
   * <p>Though the method signature doesn't say so explicitly, the returned map has {@link List}
   * values.
   */
  @Override
  public Map<K, Collection<V>> asMap() {
    return super.asMap();
  }

  /**

    @BeforeEach
    void setUp() {
        testCache = new TestBufferCacheImpl(5, 1024); // 5 buffers of 1KB each
    }

    @Test
    @DisplayName("BufferCache interface should define correct method signatures")
    void testInterfaceContract() {
        // Given
        BufferCache cache = mockBufferCache;

        // When & Then - verify interface methods exist and can be called
        assertDoesNotThrow(() -> {

func TestIAMInternalIDPConcurrencyServerSuite(t *testing.T) {
	if runtime.GOOS == globalWindowsOSName {
		t.Skip("windows is clunky")
	}

	baseTestCases := []TestSuiteCommon{
		// Init and run test on ErasureSD backend with signature v4.
		{serverType: "ErasureSD", signer: signerV4},
		// Init and run test on ErasureSD backend, with tls enabled.
		{serverType: "ErasureSD", signer: signerV4, secure: true},
		// Init and run test on Erasure backend.

        }

        @Test
        @DisplayName("Should preserve signature bytes during decode")
        void testPreserveSignatureDuringDecode() throws SMBProtocolDecodingException {
            byte[] buffer = new byte[256];
            System.arraycopy(SMBUtil.SMB2_HEADER, 0, buffer, 0, 4);

            // Create signature pattern
            byte[] testSignature = new byte[16];

	// sets the amz request id).
	httpTracerMiddleware,
	// Auth middleware verifies incoming authorization headers and routes them
	// accordingly. Client receives a HTTP error for invalid/unsupported
	// signatures.
	//
	// Validates all incoming requests to have a valid date header.
	setAuthMiddleware,
	// Redirect some pre-defined browser request paths to a static location
	// prefix.
	setBrowserRedirectMiddleware,

		return
	}
	z.ModTime, err = dc.ReadInt64()
	if err != nil {
		err = msgp.WrapError(err, "ModTime")
		return
	}
	err = dc.ReadExactBytes((z.Signature)[:])
	if err != nil {
		err = msgp.WrapError(err, "Signature")
		return
	}
	{
		var zb0002 uint8
		zb0002, err = dc.ReadUint8()
		if err != nil {
			err = msgp.WrapError(err, "Type")
			return
		}

		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErr(ErrServerNotInitialized), r.URL)
		return nil, auth.Credentials{}
	}

	for _, action := range actions {
		// Validate request signature.
		cred, adminAPIErr := checkAdminRequestAuth(ctx, r, action, "")
		switch adminAPIErr {
		case ErrNone:
			return objectAPI, cred
		case ErrAccessDenied:
			// Try another
			continue
		default: