title: Classifier does not have a companion object, and thus must be initialized here
body: <p>I have an Activity where an interface is declared and I have a <code>ViewModel</code> class which has overridden interface and want to invoke the method of interface from <code>Activity</code> to make changes in <code>ViewModel</code> class but unable to call method in <code>Activity</code> saying <strong>ViewModel class does not have a companion object, and thus must be initialized here</strong>. How to resolve this?</p>
  
  <pre><code>var selection: setSelectionSubRow? = null
      selection=RowSubTShirtViewModel
      selection!!.setNameSelection(false)
  </code></pre>
  
  <p>above code is in <code>Activity</code> whose name is <code>TShirtActivity</code>.</p>
  
  <p>below code is from <code>RowViewModel</code> class</p>
  
  <pre><code>class RowSubTShirtViewModel(private val subTShirtAdapter: SubTShirtAdapter, val context: TShirtActivity,
                          val tShirtBean: CommonItemBean, private val parentPosition: Int, private val position: Int) : BaseObservable() ,TShirtActivity.setSelectionSubRow{
  
  fun getImageDrawable(): Drawable {
      return if (tShirtBean.isSelected)
          ContextCompat.getDrawable(context, R.drawable.green_border_circle)!!
      else
          ContextCompat.getDrawable(context, R.drawable.border_circle)!!
  }
  
  override fun setNameSelection(selection: Boolean) {
      if (parentPosition == 6) {
          if (position == 1) {
              tShirtBean.isSelected = false
          }
      }
  }
  </code></pre>