title: Change Label metric unit in LibGDX
body: <p>I'm using Scene2d to build ui for my screen.</p>
  
  <pre><code>Stage stage = new Stage(new StretchViewport(Gdx.graphics.getWidth(), Gdx.graphics.getHeight()));
  Skin skin = ResourceManager.getSkin("uiskin");
  Label label = new Label("my text", skin);
  </code></pre>
  
  <p>When stage.draw() has called, the label appeared in left bottom corner of the screen. But I want to use the viewport with unit size.</p>
  
  <pre><code>float ratio = (float)Gdx.graphics.getWidth() / Gdx.graphics.getHeight();
  Stage stage = new Stage(new StretchViewport(ratio, 1));
  </code></pre>
  
  <p>In this way I can define size of other actors in percents of screen height - 0.5 , 0,23 ect. And it works well for other Actors, ImageActors, but how I can properly change size of my label? Label draw in the same place, I think, but it is tremendous for the stage, be cause its size is in pixel 183 *10 ect. And</p>
  
  <pre><code>label.setBounds(.....);
  </code></pre>
  
  <p>isn't working.</p>