title: ButterKnife: @BindView but get error saying that button instance variable is not initialized
body: <p>I am using <a href="https://github.com/JakeWharton/butterknife" rel="nofollow noreferrer">ButterKnife</a> to bind view element.</p>
  
  <p>Here is my fragment layout:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:orientation="vertical"
      android:layout_width="match_parent"
      android:layout_height="match_parent"&gt;
      ...
  
      &lt;Button
          android:id="@+id/ok_btn"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:text="@string/ok" /&gt;
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>My fragment:</p>
  
  <pre><code>class MyFragment : Fragment() {
      @BindView(R.id.ok_btn)
      lateinit var okBtn: Button
  
      ...
  
      override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
          super.onViewCreated(view, savedInstanceState)
  
          okBtn.setOnClickListener { view -&gt;
              Log.d("mytag", "ok clicked!")
          }
      }
  }
  </code></pre>
  
  <p>When I run my simple app, I get error:</p>
  
  <pre><code>Caused by: kotlin.UninitializedPropertyAccessException: lateinit property okBtn has not been initialized
  E/AndroidRuntime( 5435):    at com.my.app.MyFragment.onViewCreated(MyFragment.kt:35)
  </code></pre>
  
  <p>Why I get this error? It sounds like the <code>@BindView(R.id.ok_btn)</code> does't initialize the button instance variable. What do I miss?</p>