title: Android Java Calendar getDisplayName/s returning null
body: <pre><code>timeOfMark = Calendar.getInstance(Locale.ENGLISH);
  Map&lt;String, Integer&gt; what = timeOfMark.getDisplayNames(Calendar.HOUR, Calendar.SHORT, Locale.ENGLISH);
  
      for(Map.Entry&lt;String, Integer&gt; pair : what.entrySet())
      {
          Log.e(pair.getKey(), Integer.toString(pair.getValue()));
      }
  </code></pre>
  
  <p>This case crashes my android app, because Log.e cannot accept null string.</p>
  
  <p>It is same thing with</p>
  
  <pre><code>timeOfMark.getDisplayName(Calendar.HOUR, Calendar.SHORT, Locale.ENGLISH);
  </code></pre>
  
  <p>I tried many variations with input parameters. For locale I also did Locale.getDefault() and many other. Still same <em>*</em>*</p>
  
  <p>No darn luck. Is there anything to solve this? Or a easy workaround?</p>