Code review comment: yes,  that's a common Javadoc that signals the Java version info.

Code under review:
public static void main(String[] args) throws IOException {
        

        FormRecognizerAsyncClient client = new FormRecognizerClientBuilder()
            .credential(new AzureKeyCredential("{key}"))
            .endpoint("https:
            .buildAsyncClient();

        File analyzeFile = new File("../formrecognizer/azure-ai-formrecognizer/src/samples/java/sample-forms/"
            + "forms/Form_1.jpg");
        byte[] fileContent = Files.readAllBytes(analyzeFile.toPath());

        PollerFlux<OperationResult, List<RecognizedForm>> labeledCustomFormPoller =
            client.beginRecognizeCustomForms(new RecognizeCustomFormsOptions(
                toFluxByteBuffer(new ByteArrayInputStream(fileContent)), analyzeFile.length(), "{labeled_model_Id}")
                .setFormContentType(FormContentType.APPLICATION_PDF).setIncludeTextContent(true)
                .setPollInterval(Duration.ofSeconds(5)));

        PollerFlux<OperationResult, List<RecognizedForm>> unlabeledCustomFormPoller =
            client.beginRecognizeCustomForms(toFluxByteBuffer(new ByteArrayInputStream(fileContent)),
                analyzeFile.length(), "{unlabeled_model_Id}", FormContentType.APPLICATION_PDF);

        Mono<List<RecognizedForm>> labeledDataResult = labeledCustomFormPoller
            .last()
            .flatMap(trainingOperationResponse -> {
                if (trainingOperationResponse.getStatus().isComplete()) {
                    
                    return trainingOperationResponse.getFinalResult();
                } else {
                    return Mono.error(new RuntimeException("Polling completed unsuccessfully with status:"
                        + trainingOperationResponse.getStatus()));
                }
            });

        Mono<List<RecognizedForm>> unlabeledDataResult = unlabeledCustomFormPoller
            .last()
            .flatMap(trainingOperationResponse -> {
                if (trainingOperationResponse.getStatus().isComplete()) {
                    
                    return trainingOperationResponse.getFinalResult();
                } else {
                    return Mono.error(new RuntimeException("Polling completed unsuccessfully with status:"
                        + trainingOperationResponse.getStatus()));
                }
            });

        System.out.println("--------Recognizing forms with labeled custom model--------");
        
        
        
        
        
        labeledDataResult.subscribe(formsWithLabeledModel -> formsWithLabeledModel.forEach(labeledForm ->
            labeledForm.getFields().forEach((label, formField) -> {
                final StringBuilder boundingBoxStr = new StringBuilder();
                if (formField.getValueText().getBoundingBox() != null) {
                    formField.getValueText().getBoundingBox().getPoints().stream().map(point -> String.format("[%.2f,"
                        + " %.2f]", point.getX(), point.getY())).forEach(boundingBoxStr::append);
                }
                System.out.printf("Field %s has value %s based on %s within bounding box %s with a confidence score "
                        + "of %.2f.%n",
                    label, formField.getFieldValue(), formField.getValueText().getText(), boundingBoxStr,
                    formField.getConfidence());

                
                System.out.println("Value for a specific labeled field using the training-time label:");
                labeledForm.getFields().entrySet()
                    .stream()
                    .filter(formFieldEntry -> "Merchant".equals(formFieldEntry.getKey())) 
                    .findAny()
                    .ifPresent(formFieldEntry ->
                        System.out.printf("The Merchant name is: %s%n", formFieldEntry.getValue()));
                    
                    
                    
                    
                    
            })));

        
        
        
        try {
            TimeUnit.SECONDS.sleep(30);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        System.out.println("-----------------------------------------------------------");

        System.out.println("-------Recognizing forms with unlabeled custom model-------");
        unlabeledDataResult.subscribe(recognizedForms -> recognizedForms.forEach(unLabeledForm ->
            unLabeledForm.getFields().forEach((label, formField) -> {
                final StringBuilder boundingBoxStr = new StringBuilder();
                if (formField.getValueText().getBoundingBox() != null) {
                    formField.getValueText().getBoundingBox().getPoints().stream().map(point ->
                        String.format("[%.2f, %.2f]", point.getX(), point.getY())).forEach(boundingBoxStr::append);
                }

                final StringBuilder boundingBoxLabelStr = new StringBuilder();
                if (formField.getLabelText() != null && formField.getLabelText().getBoundingBox() != null) {
                    formField.getLabelText().getBoundingBox().getPoints().stream().map(point ->
                        String.format("[%.2f, %.2f]", point.getX(), point.getY())).forEach(boundingBoxStr::append);
                }
                System.out.printf("Field %s has label %s  within bounding box %s with a confidence score "
                        + "of %.2f.%n",
                    label, formField.getLabelText().getText(), boundingBoxLabelStr, formField.getConfidence());

                System.out.printf("Field %s has value %s based on %s within bounding box %s with a confidence "
                        + "score of %.2f.%n",
                    label, formField.getFieldValue(), formField.getValueText().getText(), boundingBoxStr,
                    formField.getConfidence());

                
                
                unLabeledForm.getFields().entrySet()
                    .stream()
                    
                    .filter(formFieldEntry -> "Vendor Name:".equals(formFieldEntry.getValue().getLabelText().getText()))
                    .findAny()
                    .ifPresent(formFieldEntry ->
                        System.out.printf("The Vendor name is: %s%n", formFieldEntry.getValue()));
                    
                    
                    
                    
            })));

        
        
        
        try {
            TimeUnit.SECONDS.sleep(30);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }


Revised code:
public static void main(String[] args) throws IOException {
        

        FormRecognizerAsyncClient client = new FormRecognizerClientBuilder()
            .credential(new AzureKeyCredential("{key}"))
            .endpoint("https:
            .buildAsyncClient();

        File analyzeFile = new File("../formrecognizer/azure-ai-formrecognizer/src/samples/java/sample-forms/"
            + "forms/Form_1.jpg");
        byte[] fileContent = Files.readAllBytes(analyzeFile.toPath());

        PollerFlux<OperationResult, List<RecognizedForm>> labeledCustomFormPoller =
            client.beginRecognizeCustomForms(new RecognizeCustomFormsOptions(
                toFluxByteBuffer(new ByteArrayInputStream(fileContent)), analyzeFile.length(), "{labeled_model_Id}")
                .setFormContentType(FormContentType.APPLICATION_PDF).setIncludeTextContent(true)
                .setPollInterval(Duration.ofSeconds(5)));

        PollerFlux<OperationResult, List<RecognizedForm>> unlabeledCustomFormPoller =
            client.beginRecognizeCustomForms(toFluxByteBuffer(new ByteArrayInputStream(fileContent)),
                analyzeFile.length(), "{unlabeled_model_Id}", FormContentType.APPLICATION_PDF);

        Mono<List<RecognizedForm>> labeledDataResult = labeledCustomFormPoller
            .last()
            .flatMap(trainingOperationResponse -> {
                if (trainingOperationResponse.getStatus().isComplete()) {
                    
                    return trainingOperationResponse.getFinalResult();
                } else {
                    return Mono.error(new RuntimeException("Polling completed unsuccessfully with status:"
                        + trainingOperationResponse.getStatus()));
                }
            });

        Mono<List<RecognizedForm>> unlabeledDataResult = unlabeledCustomFormPoller
            .last()
            .flatMap(trainingOperationResponse -> {
                if (trainingOperationResponse.getStatus().isComplete()) {
                    
                    return trainingOperationResponse.getFinalResult();
                } else {
                    return Mono.error(new RuntimeException("Polling completed unsuccessfully with status:"
                        + trainingOperationResponse.getStatus()));
                }
            });

        System.out.println("--------Recognizing forms with labeled custom model--------");
        
        
        
        
        
        labeledDataResult.subscribe(formsWithLabeledModel -> formsWithLabeledModel.forEach(labeledForm ->
            labeledForm.getFields().forEach((label, formField) -> {
                final StringBuilder boundingBoxStr = new StringBuilder();
                if (formField.getValueText().getBoundingBox() != null) {
                    formField.getValueText().getBoundingBox().getPoints().stream().map(point -> String.format("[%.2f,"
                        + " %.2f]", point.getX(), point.getY())).forEach(boundingBoxStr::append);
                }
                System.out.printf("Field %s has value %s based on %s within bounding box %s with a confidence score "
                        + "of %.2f.%n",
                    label, formField.getFieldValue(), formField.getValueText().getText(), boundingBoxStr,
                    formField.getConfidence());

                
                System.out.println("Value for a specific labeled field using the training-time label:");
                labeledForm.getFields().entrySet()
                    .stream()
                    .filter(formFieldEntry -> "Merchant".equals(formFieldEntry.getKey())) 
                    .findAny()
                    .ifPresent(formFieldEntry ->
                        System.out.printf("The Merchant name is: %s%n", formFieldEntry.getValue()));
                    
                    
                    
                    
                    
            })));

        
        
        
        try {
            TimeUnit.SECONDS.sleep(30);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        System.out.println("-----------------------------------------------------------");

        System.out.println("-------Recognizing forms with unlabeled custom model-------");
        unlabeledDataResult.subscribe(recognizedForms -> recognizedForms.forEach(unLabeledForm ->
            unLabeledForm.getFields().forEach((label, formField) -> {
                final StringBuilder boundingBoxStr = new StringBuilder();
                if (formField.getValueText().getBoundingBox() != null) {
                    formField.getValueText().getBoundingBox().getPoints().stream().map(point ->
                        String.format("[%.2f, %.2f]", point.getX(), point.getY())).forEach(boundingBoxStr::append);
                }

                final StringBuilder boundingBoxLabelStr = new StringBuilder();
                if (formField.getLabelText() != null && formField.getLabelText().getBoundingBox() != null) {
                    formField.getLabelText().getBoundingBox().getPoints().stream().map(point ->
                        String.format("[%.2f, %.2f]", point.getX(), point.getY())).forEach(boundingBoxStr::append);
                }
                System.out.printf("Field %s has label %s  within bounding box %s with a confidence score "
                        + "of %.2f.%n",
                    label, formField.getLabelText().getText(), boundingBoxLabelStr, formField.getConfidence());

                System.out.printf("Field %s has value %s based on %s within bounding box %s with a confidence "
                        + "score of %.2f.%n",
                    label, formField.getFieldValue(), formField.getValueText().getText(), boundingBoxStr,
                    formField.getConfidence());

                
                
                unLabeledForm.getFields().entrySet()
                    .stream()
                    
                    .filter(formFieldEntry -> "Vendor Name:".equals(formFieldEntry.getValue().getLabelText().getText()))
                    .findAny()
                    .ifPresent(formFieldEntry ->
                        System.out.printf("The Vendor name is: %s%n", formFieldEntry.getValue()));
                    
                    
                    
                    
            })));

        
        
        
        try {
            TimeUnit.SECONDS.sleep(30);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }