return strings.HasPrefix(r.Header.Get(xhttp.Authorization), jwtAlgorithm)
}

// Verify if request has AWS Signature Version '4'.
func isRequestSignatureV4(r *http.Request) bool {
	return strings.HasPrefix(r.Header.Get(xhttp.Authorization), signV4Algorithm)
}

// Verify if request has AWS Signature Version '2'.
func isRequestSignatureV2(r *http.Request) bool {

      }
      return builder.build();
    }
  }

  private static final class Signature {
    private final String name;
    private final ImmutableList<Class<?>> parameterTypes;

    Signature(Method method) {
      this(method.getName(), ImmutableList.copyOf(method.getParameterTypes()));
    }

    Signature(String name, ImmutableList<Class<?>> parameterTypes) {
      this.name = name;

			fv:   defaultFormVals.Clone().Set(xhttp.AmzSignature, "my-signature"),
		},
		{
			name: "XIgnoreFoo does not have to appear in policy",
			fv:   defaultFormVals.Clone().Set("X-Ignore-Foo", "my-foo-value"),
		},
		{
			name: "File does not have to appear in policy",
			fv:   defaultFormVals.Clone().Set("File", "file-value"),
		},
		{
			name: "Signature does not have to appear in policy",

        // Assert
        assertTrue(result, "Verify should return true for valid signature");
        verify(signingDigest, times(1)).verify(testData, offset, length, extraPad, message);
    }

    @Test
    @DisplayName("Test verify method returns false for invalid signature")
    void testVerifyReturnsFalse() {
        // Arrange
        int offset = 0;
        int length = testData.length;

      }
      return builder.build();
    }
  }

  private static final class Signature {
    private final String name;
    private final ImmutableList<Class<?>> parameterTypes;

    Signature(Method method) {
      this(method.getName(), ImmutableList.copyOf(method.getParameterTypes()));
    }

    Signature(String name, ImmutableList<Class<?>> parameterTypes) {
      this.name = name;

     */
    @Override
    public boolean verifySignature(final byte[] buffer, final int i, final int size) {
        // observed too that signatures on error responses are sometimes wrong??
        // Looks like the failure case also is just reflecting back the signature we sent

        // with SMB3's negotiation validation it's no longer possible to ignore this (on the validation response)

        // For now, we test that the method signature is correct and can be called

        AtomicInteger callbackCount = new AtomicInteger(0);

        try {
            // This will likely fail due to missing SearchEngineClient setup,
            // but we can verify the method signature and basic functionality
            SearchEngineUtil.scroll("test_index", hit -> {

	tmp := struct {
		VersionID string
		ModTime   time.Time
		Signature string
		Type      uint8
		Flags     uint8
	}{
		VersionID: hex.EncodeToString(z.VersionID[:]),
		ModTime:   time.Unix(0, z.ModTime),
		Signature: hex.EncodeToString(z.Signature[:]),
		Type:      z.Type,
		Flags:     z.Flags,
	}
	return json.Marshal(tmp)

xlHeaderVersion version == 1:

```
//msgp:tuple xlMetaV2VersionHeader
type xlMetaV2VersionHeader struct {
 VersionID [16]byte  // Version UUID, raw.
 ModTime   int64     // Unix nanoseconds.
 Signature [4]byte   // Signature of metadata.
 Type      uint8     // Type if the version
 Flags     uint8
}
```

The following flags are defined:

```
const (
 FreeVersion = 1 << 0
 UsesDataDir = 1 << 1

  if (TF_GetCode(status) != TF_OK) return;

  tensorflow::GradientDef gdef;
  gdef.set_function_name(func->record->fdef().signature().name());
  gdef.set_gradient_func(grad->record->fdef().signature().name());
  status->status = g->graph.AddGradientDef(std::move(gdef));
}

int TF_GraphNumFunctions(TF_Graph* g) {
  tensorflow::mutex_lock l(g->mu);