How to use the tns-core-modules/ui/button.Button function in tns-core-modules

public test_codesnippets() {
        // >> dock-layout-create
        var dockLayout = new dockModule.DockLayout();
        //  << dock-layout-create

        // >> dock-layout-addchild
        var btn = new button.Button();
        dockLayout.addChild(btn);
        // << dock-layout-addchild

        // >> dock-layout-removechild
        dockLayout.removeChild(btn);
        // << dock-layout-removechild

        // >> dock-layout-setdocl
        var btnDockedToRight = new button.Button();
        dockModule.DockLayout.setDock(btnDockedToRight, enums.Dock.right);
        dockLayout.addChild(btnDockedToRight);
        // << dock-layout-setdocl
    }

frame.topmost().goBack();
    });
    stack.addChild(backBtn);

    var txt = new text.TextField();
    txt.text = "text B";
    stack.addChild(txt);

    var sv = new scroll.ScrollView();
    sv.height = 200;
    stack.addChild(sv);

    var content = new stackModule.StackLayout();
    sv.content = content;
    for (var i = 0; i < 50; i++) {
        var b = new button.Button();
        b.text = "button " + i;
        content.addChild(b);
    }

    page.content = stack;

    return page;
}
//export var Page = page;

export function createPage() {
    var width = 200;
    var textAlignment = enums.TextAlignment.right;

    var stack = new stackLayoutModule.StackLayout();
    var view;

    view = new buttonModule.Button();
    view.width = width;
    view.style.backgroundColor = new colorModule.Color("Blue");
    view.style.textAlignment = textAlignment;
    view.text = "Button";
    stack.addChild(view);

    view = new labelModule.Label();
    view.width = width;
    view.text = "Label";
    view.style.backgroundColor = new colorModule.Color("Green");
    view.style.textAlignment = textAlignment;
    stack.addChild(view);

    view = new textFieldModule.TextField();
    view.width = width;
    view.text = "TextField";

export function createPage() {

    var page = new pageModule.Page();
    var stack = new stackLayoutModule.StackLayout();
    var sourceOneWay = new observableModule.Observable();
    var sourceTwoWay = new observableModule.Observable();
    var targetOneWay = new textFieldModule.TextField();
    var targetTwoWay = new textFieldModule.TextField();
    var buttonOneWay = new buttonModule.Button();
    var buttonTwoWay = new buttonModule.Button();
    var buttonSetText = new buttonModule.Button();

    targetOneWay.id = "textFieldOneWay";
    targetTwoWay.id = "textFieldTwoWay";
    buttonOneWay.id = "buttonOneWay";
    buttonTwoWay.id = "buttonTwoWay";
    buttonSetText.id = "buttonSetText";    

    targetOneWay.automationText = "textFieldOneWay";
    targetTwoWay.automationText = "textFieldTwoWay";
    buttonSetText.automationText = "buttonSetText";
    //buttonOneWay.automationText = "buttonOneWay";    
    //buttonTwoWay.automationText = "buttonTwoWay";    

    buttonSetText.text = "SetText";

export function createPage() {
    var stackLayout = new stackLayoutDef.StackLayout();

    var btn = new MyButton();
    btn.text = "Alabala";
    btn.id = "btn";

    var btn1 = new MyButton();
    btn1.text = "Alabala";
    btn1.id = "btn1";
    
    var btn2 = new buttonModule.Button();
    btn2.text = "Alabala";
    
    stackLayout.addChild(btn);
    stackLayout.addChild(btn1);
    stackLayout.addChild(btn2);
    
    var page = new pages.Page();
    page.css = "#btn {font-family: Courier New} #btn1 {font-family: Times New Roman} #btn2 {color: yellow}";
    page.content = stackLayout;
    return page;
}

export function createPage() {

    var stack = new stackLayoutModule.StackLayout();
    var labelHeight = Math.round(deviceProperties.screen.mainScreen.heightPixels / (7 * deviceProperties.screen.mainScreen.scale));
    var stopButton = new button.Button();
    stopButton.text = "Stop Detecting Gestures";
    stack.addChild(stopButton);

    var tapLabel = new labelModule.Label();
    tapLabel.text = "Tap here";
    stack.addChild(tapLabel);

    var doubletapLabel = new labelModule.Label();
    doubletapLabel.text = "Double Tap here";
    stack.addChild(doubletapLabel);

    var longpressLabel = new labelModule.Label();
    longpressLabel.text = "Long Press here";
    stack.addChild(longpressLabel);

    var swipeLabel = new labelModule.Label();

export function createPage() {

    var stack = new stackModule.StackLayout();

    var btn = new button.Button();
    btn.text = "Alert";
    btn.on(button.Button.tapEvent, function () {
        alert("Alert is global");
    });

    stack.addChild(btn);

    var page = new pages.Page();
    page.content = stack;
    return page;
}

export function createPage() {
    var page = new pages.Page();
    var stack = new stackModule.StackLayout();

    var btn = new button.Button();
    btn.text = "Page B new activity";
    btn.on(button.Button.tapEvent, function () {
        var nextPage = "tests/pages/navigation/pageB-new-activity";
        frame.topmost().navigate(nextPage);
    });
    stack.addChild(btn);

    var txt = new text.TextField();
    txt.text = "text new A";
    stack.addChild(txt);

    page.content = stack;

    return page;
}
//export var Page = page;

public test_setInvalidDock_Throws() {
        var testBtn = new button.Button();

        TKUnit.assertThrows(() => {
            dockModule.DockLayout.setDock(testBtn, "invalid");
        });
    }

Grid.addRow(secondRow);
    GridLayout.setRow(Label1,0);
    GridLayout.setRow(Label2,1);


    let stack2 = new StackLayout();
    let image = new Image();
    image.src="~/images/apple.jpg"
    image.height=100;
    image.width=100;
    stack2.verticalAlignment = "middle";
    stack2.addChild(image);
    

    let stack3 = new StackLayout();
    let button = new Button();
    button.text="Click me!";
    button.width=100;
    button.textAlignment = "center";
    stack3.verticalAlignment = "middle";
    stack3.addChild(button);


    this.stackItems = [stack3,stack2,Grid];

            

    
  }