baseviewmodel.kt

abstract class BaseViewModel: ViewModel() {
    protected operator fun <T> LiveData<T>.invoke(value: T) {
        if (this is ViewModelLiveData) {
            val viewModelLiveData = this
            viewModelLiveData.setValue(value)
        }
    }

    protected fun <T> liveData(value: T) =  lazy {
        ViewModelLiveData(value) as LiveData<T>
    }

    protected fun <T> liveData() =  lazy {
        ViewModelLiveData<T>() as LiveData<T>
    }

    private class ViewModelLiveData<T> : LiveData<T>{
        constructor(value: T) : super(value)
        constructor() : super()

        public override fun setValue(value: T) {
            super.setValue(value)
        }

    }
}