Layout_anchor equivalent for ConstraintLayout
<android.support.design.widget.FloatingActionButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="@dimen/activity_horizontal_margin"
android:scaleType="center"
android:src="@drawable/ic_star"
app:fabSize="mini"
app:layout_constraintBottom_toBottomOf="@+id/above_layout"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="@+id/above_layout"/>