Save state for android custom view

SavedState.kt

 internal class SavedState : BaseSavedState {
        var isExpanded: Boolean = false

        constructor(superState: Parcelable) : super(superState)

        constructor(source: Parcel) : super(source) {
            isExpanded = source.readBoolean()
        }

        constructor(source: Parcel?, loader: ClassLoader?) : super(source, loader)

        override fun writeToParcel(out: Parcel, flags: Int) {
            super.writeToParcel(out, flags)
            out.writeBoolean(isExpanded)
        }

        companion object {
            @JvmField
            val CREATOR: Parcelable.Creator<SavedState> = object : Parcelable.Creator<SavedState> {
                override fun createFromParcel(source: Parcel) = SavedState(source)
                override fun newArray(size: Int): Array<SavedState> = newArray(size)
            }
        }
    }