@Test
public void shouldHaveNewFragment() throws Exception
{
    NewActivity newActivity = new NewActivity();
    assertNotNull( newActivity.getSupportFragmentManager().findFragmentById( R.id.new_fragment ) );
}

<!--Fragment XML declaration-->
<fragment
    android:id="@+id/new_fragment"
    android:name="com.colabug.NewFragment"
    android:layout_width="match_parent"
    android:layout_height="match_parent"/>