title: How to check empty spaces in draft js Editor
body: <p>How i can check empty there are empty spaces in editor?
  i don't want to submit form when there are empty spaces in editor.
  i'm using  this function that detect is editor is empty or not but it does not detect is editor has empty spaces or not </p>
  
  <pre><code>contentState.hasText()
  </code></pre>