From the Trenches: Tabs with the Apex Toolkit, part 1

        //Start of payment tab. You will use the methods here: https://developers.docusign.com/docs/salesforce/apex-toolkit-reference/paymenttab.html
        
        // Create a numbertab to use in the lineItem object. 
        // The datalabel is important because you use the exact same data label in the line item shown below
        // WithValue is the amount of the payment and the number tab uses an anchor, but you could also use withPosition instead
        dfsle.Tab Numtab = new dfsle.NumberTab()
            .withRequired(true) // If you set this to false the payment is optional. 
            .withValue('4') // Payment of $4
            .withReadOnly(true) 
            .withDataLabel('PaymentAmount')
            .withAnchor(new dfsle.Tab.Anchor('Payment Amount', true, true, null, true, true, 'pixels', 120, 0)); 
        
        
        // Before you create the actual payment, you have to first create the payment line item
        // The reason for this is that the payment method below uses a payment line item as a parameter. 
        // Notice the last parameter matches the datalabel of the number tab shown above
        dfsle.PaymentTab.LineItem myPaymentLineItem = new dfsle.PaymentTab.LineItem(
            'Test', // Name: This is a sender-defined product name, service name, or other designation for the line item.
            null, // Description: An optional sender-defined description of the line item.
            null, // itemCode: This is an optional sender-defined SKU, inventory number, or other item code for the line item.
            'PaymentAmount'); // This is the tab dataLabel that specifies the amount paid for the line items. The dataLabel matches the numberTab's label defined above
        
        // You need to get the UUID of a payment gateway. The ID is found under "Settings" -> "Payment Gateways"
        dfsle.UUID paymentGateWayId = dfsle.UUID.parse('73649529-xxxx-xxxx-xxxx-0fe432f1ec07'); 
        
        // When you create the payment it requires a list of line items
        List<dfsle.PaymentTab.LineItem> listofLineItems = new List<dfsle.PaymentTab.LineItem>(); 
        listofLineItems.add(myPaymentLineItem);
        
        // When you create the payment it requires a list of payment methods
        String[] paymentMethods = new List<String>();
        paymentMethods.add('CreditCard');
       
        
        // Create the actual payment using the PaymentTab.Payment 
        dfsle.PaymentTab.Payment payment = new dfsle.PaymentTab.Payment(
            paymentGateWayId, // Docusign Gateway: A GUID that identifies the payment gateway connected to the sender's Docusign account.
            null, //Customer ID: The customer ID
            null, // Source ID: The payment source ID.
            paymentMethods, // Payment-Methods: An array of accepted payment methods.
            'USD', // Currency code: Specifies the three-letter ISO 4217 currency code for the payment.
            listofLineItems, // LineItems: A payment formula can have one or more line items that provide detail about individual items in a payment request. The list of line items are returned as metadata to the payment gateway.
            true, // Authorize: When true, the payment details will be used to collect payment.
            false, // Save: When true, the signer's payment method (credit card or bank account) will be saved to the sender's payment gateway.
            null, // Custom metadata: This is a sender-defined field that passes any extra metadata about the payment that will show up in the Authorize.net transaction under “Description” in the merchant gateway portal.
            false); // Custom metadata required: A sender-defined field that specifies whether custom metadata is required for the transaction. When set to true, custom metadata is required.
        
        // Last, create the payment tab that appears on the document 
        dfsle.Tab myPaymentTab = new dfsle.PaymentTab()
            .withPayment(payment) 
            .withRequired(false) 
            // Define the position which is required but it won't have impact because the positioning comes from the position of the "Numtab" field
            .withPosition(new dfsle.Tab.Position(
                1, // The document to use
                1, // Page number on the document
                220, // X position
                300, // Y position
                100, // 100 pixels wide
                null)) 
            .withDataLabel('PaymentTest');
        // END of Payment tab
        
        // Add tab to recipient: 
        myRecipient.withTabs(new List<dfsle.Tab> {myPaymentTab, Numtab});

  dfsle.RadioGroupTab radioGroup = new dfsle.RadioGroupTab();
        
List<dfsle.RadioGroupTab.Radio> radios = new List<dfsle.RadioGroupTab.Radio>{   
            new dfsle.RadioGroupTab.Radio(1, new dfsle.RadioGroupTab.Position(1, 200, 350), null, null, 'yes', false, false, true),
            new dfsle.RadioGroupTab.Radio(1, new dfsle.RadioGroupTab.Position(1, 200, 400), null, null, 'no', false, false, true)
};
                    
dfsle.Tab.Position pos = new dfsle.Tab.Position( 
            1, // The document to use 
            1, // Page number on the document 
            null, // X position 
            null, // Y position 
            null, // Width 
            null); // Height
        
radioGroup.withRadios(radios).withPosition(pos); 
        
myRecipient.withTabs(new List<dfsle.Tab> {radioGroup});

       // Define the first number to add
        dfsle.Tab a = new dfsle.numberTab()
            .withValue('4')
            .withReadOnly(false) // locked 
            .withDataLabel('a') 
            .withAnchor(new dfsle.Tab.Anchor(
                'FirstNumber', // Anchor string
                false, // Do not allow white space in anchor string
                false, // Anchor string is not case-sensitive
                'right', // Horizontal alignment in relation to the anchor text
                true, // Ignore if the anchor text is not present in the document
                true, // Must match the value of the anchor string in its entirety
                'pixels', // Unit of the X and Y offset properties
                10, // X offset
                0)); // Y offset
                
        
        //Define the second number to add
        dfsle.Tab b = new dfsle.numberTab()
            .withValue('5')
            .withReadOnly(false) // locked 
            .withDataLabel('b') 
            .withAnchor(new dfsle.Tab.Anchor(
                'SecondNumber', // Anchor string
                false, // Do not allow white space in anchor string
                false, // Anchor string is not case sensitive
                'right', // Horizontal alignment in relation to the anchor text
                true, // Ignore if the anchor text is not present in the document
                true, // Must match the value of the anchor string in its entirety
                'pixels', // Unit of the X and Y offset properties
                10, // X offset
                0)); // Y offset
        
        //Add the two numbers together using a formula 
        dfsle.Tab formulaOne= new dfsle.FormulaTab()
            // For the formula to work, you need to tell it which tabs to work with and what operation 
            //In this case you are adding together the a and b tabs shown above based on their data labels 
            .withFormula('[b] + [a]') 
                .withAnchor(new dfsle.Tab.Anchor(
                'TotalValue', // Anchor string
                false, // Do not allow white space in anchor string
                false, // Anchor string is not case sensitive
                'right', // Horizontal alignment in relation to the anchor text
                true, // Ignore if the anchor text is not present in the document
                true, // Must match the value of the anchor string in its entirety
                'pixels', // Unit of the X and Y offset properties
                20, // X offset
                0)); // Y offset
                
        myRecipient = myRecipient.withTabs(new List<dfsle.Tab> {a,b, formulaOne});