如何从扩展RelativeLayout的类中更改活动中的文本视图文本

public class CustomRelativeLayout extends RelativeLayout {
    
    public CustomRelativeLayout(Context context) {
        super(context);
    }

    public CustomRelativeLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public CustomRelativeLayout(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }
    
    public void updateTextViewText(TextView textView, String newText) {
        textView.setText(newText);
    }
}

public class MainActivity extends AppCompatActivity {

    private CustomRelativeLayout customRelativeLayout;
    private TextView textView;

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

        customRelativeLayout = findViewById(R.id.customRelativeLayout);
        textView = findViewById(R.id.textView);

        String newText = "新的文本内容";
        customRelativeLayout.updateTextViewText(textView, newText);
    }
}

<com.example.app.CustomRelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/customRelativeLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="初始文本内容" />

</com.example.app.CustomRelativeLayout>