      
      - Discussion: Maestro cards need a start date or an issue number to be entered for making any transaction
      
-     - parameter isVisible: whether start date and issue number fields should be visible
+     - parameter isVisible: Whether start date and issue number fields should be visible
      */
     public func toggleStartDateVisibility(isVisible: Bool) {
         self.maestroFieldsHeightConstraint?.constant = isVisible ? inputFieldHeight : 0

    /**
    Delegate method that is triggered when the issueNumberInputField entered a code
    
    - parameter input:       the issueNumberInputField calling the delegate method
    - parameter issueNumber: the issue number that has been entered as a String
    */
    public func issueNumberInputDidEnterCode(inputField: IssueNumberInputField, issueNumber: String) {
        if issueNumber.characters.count == 3 {

        self.hintLabel.numberOfLines = 3
        self.hintLabel.translatesAutoresizingMaskIntoConstraints = false
        
        // Layout constraints
        self.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("|[scrollView]|", options: NSLayoutFormatOptions(rawValue: 0), metrics: nil, views: ["scrollView":contentView]))
        self.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:|[scrollView]-1-[button]", options: NSLayoutFormatOptions(rawValue: 0), metrics: nil, views: ["scrollView":contentView, "button":paymentButton]))
        
