void ngSwitch=(value)

Source 

set ngSwitch(dynamic value) {
  // Empty the currently active ViewContainers
  this._emptyAllActiveViews();
  // Add the ViewContainers matching the value (with a fallback to default)
  this._useDefault = false;
  var views = this._valueViews[value];
  if (views == null) {
    this._useDefault = true;
    views = this._valueViews[_WHEN_DEFAULT];
  }
  this._activateViews(views);
  this._switchValue = value;
}