Need help with identifying go to the top and bottom functions about tbkeys HOT 6 OPEN

window.goDoCommand('cmd_scrollTop');
window.goDoCommand('cmd_scrollBottom');
window.goDoCommand('cmd_moveUp2');
window.goDoCommand('cmd_moveDown2');
window.goDoCommand('cmd_moveTop');
window.goDoCommand('cmd_moveBottom');

The quick brown fox jumps over the lazy dog.
The quick brown fox jumps over the lazy dog.
The quick brown fox jumps over the lazy dog.

(function () {
  var tree = window.document.getElementById('threadTree');
  tree.ensureRowIsVisible(0);
  tree.view.selection.select(0);
})();

(function () {
  var tree = window.document.getElementById('threadTree');
  var rowCount = tree.view.rowCount;
  tree.ensureRowIsVisible(rowCount - 1);
  tree.view.selection.select(rowCount - 1);
})();

(function () {
  var tree = window.document.getElementById('threadTree');
  var currentIndex = tree.view.selection.currentIndex;
  var pageUpIndex = currentIndex - (tree.getPageLength() - 1);
  if (pageUpIndex < 0) {
    tree.ensureRowIsVisible(0);
    tree.view.selection.select(0);
  } else {
    tree.ensureRowIsVisible(pageUpIndex);
    tree.view.selection.select(pageUpIndex);
  }
})();

(function () {
  var tree = window.document.getElementById('threadTree');
  var rowCount = tree.view.rowCount;
  var currentIndex = tree.view.selection.currentIndex;
  var pageDownIndex = currentIndex + (tree.getPageLength() - 1);
  if (pageDownIndex > rowCount - 1) {
    tree.ensureRowIsVisible(rowCount - 1);
    tree.view.selection.select(rowCount - 1);
  } else {
    tree.ensureRowIsVisible(pageDownIndex);
    tree.view.selection.select(pageDownIndex);
  }
})();

{
  "home": "window.alert('home');",
  "end": "window.alert('end');",
  "shift+home": "window.alert('shift+home');",
  "shift+end": "window.alert('shift+end');"
}

{
  "home": "cmd:cmd_moveUp2",
  "end": "cmd:cmd_moveDown2",
  "shift+home": "cmd:cmd_selectUp2",
  "shift+end": "cmd:cmd_selectDown2"
}