function WebUiButtonWithDropDownPanelJS(
   settings
The settings of button. The settings parameter has the following properties:
 
 
horizontalAlignMode (object): WebHorizontalAlignModeEnumJS object that defines horizontal alignment of drop-down panel with UI elements. Default value is WebHorizontalAlignModeEnumJS.StartAtLeft. 
 
verticalAlignMode (object): WebVerticalAlignModeEnumJS object that defines horizontal alignment of drop-down panel with UI elements. Default value is WebVerticalAlignModeEnumJS.StartAtBottom. 
 
cssClass (string): CSS class or classes that will be applied to the element. Example: "cssClass:'button remove'".
 
css (object): Object, which contains the names and values of CSS properties. Example: "css:{'width':'100px', 'height':'50px'}".
 Important: all CSS related to vertical positioning will be ignored if "verticalAlignMode" is not "Custom".
 Important: all CSS related to horizontal positioning will be ignored if "horizontalAlignMode" is not "Custom". 
 
properties (object): Object, which contains the names and values of element attributes. Example: "properties:{'title':'Hello', 'id':'helloId'}"
 
events (object): Object, which contains the callbacks of events. Each object property has the following parameters:
 
 
Property name - event name (Example: "click", "change", "mouseover" etc ).
 
Property value - event callback OR object - {callback:callback, data: Object, that contains additional data that will be passed to the callback}.
 
 Example:"events:{'click':function(){console.log('click');}, 'change':{callback:function(){console.log('change');}, data:{x:11} } }".
 
 
states (object): An instance of WebUiElementStateCollectionJS class.
 
title (string): Shortcut for 'title' attribute of element (equals - "properties:{'title':'some title'}"). Important: If 'states' is defined and active state WebUiElementJS.get_ActiveState has title, the UI element will have title of active state. 
 
id (string): Shortcut for 'id' attribute of element (equals - "properties:{'id':'elementId'}").
 
onClick (object): Shortcut for 'click' event callback.
 
onChange (object): Shortcut for 'change' event callback.
 
localizationId (string): Unique localization ID.
 
 : object, 
   container
WebUiElementContainerJS object.
 : WebUiElementContainerJS
) : WebUiButtonWithDropDownPanelJS;