return None
    return f"{client_id}_tag"


@app.get("/foo")
def foo_handler(
    client_key: str = Depends(_get_client_key),
    client_tag: Optional[str] = Depends(_get_client_tag),
):
    return {"client_id": client_key, "client_tag": client_tag}


client = TestClient(app)

expected_schema = {
    "components": {
        "schemas": {
            "HTTPValidationError": {

func isReqAuthenticated(ctx context.Context, r *http.Request, region string, stype serviceType) (s3Error APIErrorCode) {
	if errCode := reqSignatureV4Verify(r, region, stype); errCode != ErrNone {
		return errCode
	}

	clientETag, err := etag.FromContentMD5(r.Header)
	if err != nil {
		return ErrInvalidDigest
	}

	// Extract either 'X-Amz-Content-Sha256' header or 'X-Amz-Content-Sha256' query parameter (if V4 presigned)

	}

	// X-Amz-Copy-Source shouldn't be set for this call.
	if _, ok := r.Header[xhttp.AmzCopySource]; ok {
		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrInvalidCopySource), r.URL)
		return
	}

	clientETag, err := etag.FromContentMD5(r.Header)
	if err != nil {
		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrInvalidDigest), r.URL)
		return
	}

	// if Content-Length is unknown/missing, throw away

	}

	policyBytes, err := base64.StdEncoding.DecodeString(formValues.Get("Policy"))
	if err != nil {
		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrMalformedPOSTRequest), r.URL)
		return
	}

	clientETag, err := etag.FromContentMD5(formValues)
	if err != nil {
		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrInvalidDigest), r.URL)
		return
	}

	var forceMD5 []byte

	if sc := r.Header.Get(xhttp.AmzStorageClass); sc != "" {
		if !storageclass.IsValid(sc) {
			writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrInvalidStorageClass), r.URL)
			return
		}
	}

	clientETag, err := etag.FromContentMD5(r.Header)
	if err != nil {
		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrInvalidDigest), r.URL)
		return
	}

	// if Content-Length is unknown/missing, deny the request