title: Why is `robot.keyRelease(KeyEvent.VK_CONTROL)` necessary?
body: <p>When using Robot class, what is the meaning of: </p>
  
  <pre><code>robot.keyRelease(KeyEvent.VK_CONTROL);
  </code></pre>
  
  <p>Shouldn't the code below be sufficient to send the event?</p>
  
  <pre><code>Robot robot = new Robot();
  robot.keyPress(KeyEvent.VK_CONTROL);
  </code></pre>