title: Unable to use the methods of GraphicsDevice
body: <p>I've been trying to learn MonoGame from their official documentation.</p>
  
  <p>However, I've hit a snag.</p>
  
  <p>In their code, they've done the following...</p>
  
  <pre><code>Vector2 playerPosition = new Vector2(GraphicsDevice.Viewport.TitleSafeArea.X,
  GraphicsDevice.Viewport.TitleSafeArea.Y + GraphicsDevice.Viewport.Height / 2);
  </code></pre>
  
  <p>Now, the problem I'm getting is this. Whenever I use the bit of code <code>GraphicsDevice.Viewport</code>, MonoGame does not allow it and gives the following error:</p>
  
  <blockquote>
    <p>An object reference is required for the non-static field, method or property 'GraphicsDevice.Viewport'</p>
  </blockquote>
  
  <p>What can I do to fix this error?</p>