For nulling something on destroy, primary motivation, a better way to do view binding.

NullOnDestroy.kt

/**
 * Delegate for use in fragments
 *
 * When the fragment's view is destroyed the field will be set to null.
 * This happens immediately before the fragment's onDestroyView() is called.
 *
 * Additionally, this delegate gives the same behavior as lateinit.
 *
 * Property should be a non-nullable var.
 */
fun <T : Any> Fragment.nullOnDestroy(): NullOnDestroy<T> = NullOnDestroy(this)

class NullOnDestroy<T : Any>(
    fragment: Fragment
) : ReadWriteProperty<Fragment, T>, LifecycleObserver {

    private var value: T? = null

    init {
        fragment.viewLifecycleOwnerLiveData.observeForever {
            it?.lifecycle?.addObserver(this)
        }
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_DESTROY)
    fun onDestroy() {
        value = null
    }

    override fun getValue(thisRef: Fragment, property: KProperty<*>): T {
        return value ?: throw IllegalStateException("Property ${property.name} should be initialized before get.")
    }

    override fun setValue(thisRef: Fragment, property: KProperty<*>, value: T) {
        this.value = value
    }
}