__init__(value, choices, options) {
		this.super('__init__', [ value, choices, Object.assign({
			sort: true
		}, options, {
			multiple: false,
			create: false,
			optional: false
		}) ]);
	}
ComboButtons support the same properties as
[Dropdown.InitOptions]{@link LuCI.ui.Dropdown.InitOptions} but enforce
specific values for some properties and add additional button specific
properties.

@typedef {LuCI.ui.Dropdown.InitOptions} InitOptions
@memberof LuCI.ui.ComboButton

@property {boolean} multiple=false
Since ComboButtons never allow selecting multiple actions, this property
is forcibly set to `false`.

@property {boolean} create=false
Since ComboButtons never allow creating custom choices, this property
is forcibly set to `false`.

@property {boolean} optional=false
Since ComboButtons must always select one action, this property is
forcibly set to `false`.

@property {Object<string, string>} [classes]
Specifies a mapping of choice values to CSS class names. If an action
choice is selected by the user and if a corresponding entry exists in
the `classes` object, the class names corresponding to the selected
value are set on the button element.

This is useful to apply different button styles, such as colors, to the
combined button depending on the selected action.

@property {function} [click]
Specifies a handler function to invoke when the user clicks the button.
This function will be called with the button DOM node as `this` context
and receive the DOM click event as first as well as the selected action
choice value as second argument.