Loaded as one of the BaseStyleSpecification extensions, based on the value of the type key.
ActivityBarStyleSpecification | ButtonStyleSpecification | CameraStyleSpecification | CheckBoxStyleSpecification | DropDownStyleSpecification | FlowStyleSpecification | FrameStyleSpecification | GraphStyleSpecification | HorizontalFlowStyleSpecification | LineStyleSpecification | ImageStyleSpecification | LabelStyleSpecification | ListBoxStyleSpecification | ProgressBarStyleSpecification | RadioButtonStyleSpecification | HorizontalScrollBarStyleSpecification | VerticalScrollBarStyleSpecification | ScrollPaneStyleSpecification | SliderStyleSpecification | SwitchStyleSpecification | TableStyleSpecification | TabStyleSpecification | TextBoxStyleSpecification | VerticalFlowStyleSpecification | TabbedPaneStyleSpecification | EmptyWidgetStyleSpecification | MinimapStyleSpecification | TechnologySlotStyleSpecification | GlowStyleSpecification | SpeechBubbleStyleSpecification | DoubleSliderStyleSpecification