I've added 2 textviews in ConstrainLayout in code, but i can't see them. 
The screen is empty.
Please can anybody help me to figure out this?
Thanks a lot!

```
public class ActivitySixth extends AppCompatActivity {
    private TextView tv1;
    private TextView tv3;
    private ConstraintLayout mConstraintLayout;
    private static final int ID_CONS_LAY = 160;
    private static final int ID_TV1 = 160;
    private static final int ID_TV3 = 160;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_sixth);

        mConstraintLayout = findViewById(R.id.parent_Constraint);
        ConstraintSet set = new ConstraintSet();
        set.clone(mConstraintLayout);

        tv1 = new TextView(this);
        tv3 = new TextView(this);

       tv1.setText("TextView number ONE");
       tv3.setText("TextView number THREE");

       tv1.setId(ID_TV1);
       tv3.setId(ID_TV3);

       mConstraintLayout.addView(tv1);
       mConstraintLayout.addView(tv3);

       set.connect(tv1.getId(), ConstraintSet.LEFT, R.id.parent_Constraint, ConstraintSet.LEFT, 0);
       set.connect(tv3.getId(), ConstraintSet.RIGHT, R.id.parent_Constraint, ConstraintSet.RIGHT, 0);
       set.applyTo(mConstraintLayout);
}

```

}