GutterConfig
constructor(type: GutterType? = null, lineMarker: (EditorSession, Int) -> GutterMarker?? = null, lineMarkerChange: (ViewUpdate) -> Boolean? = null, lineMarkerClick: (EditorSession, Int) -> Boolean? = null, renderEmptyElements: Boolean = false, initialSpacer: (EditorSession) -> GutterMarker? = null, updateSpacer: (GutterMarker, ViewUpdate) -> GutterMarker? = null)