Event Msg Helper. Listen only one Event for LiveData

EventMsg.kt

package com.vk.android.utils

import androidx.lifecycle.Observer

open class EventMsg<out T>(private val content: T) {

    var hasBeenHandled = false
        private set // Allow external read but not write

    fun getContentIfNotHandled(): T? {
        return if (hasBeenHandled) {
            null
        } else {
            hasBeenHandled = true
            content
        }
    }

    fun peekContent(): T = content
}

class EventObserver<T>(private val onEventUnhandledContent: (T) -> Unit) : Observer<EventMsg<T>> {
    override fun onChanged(eventMsg: EventMsg<T>?) {
        eventMsg?.getContentIfNotHandled()?.let {
            onEventUnhandledContent(it)
        }
    }
}