title: How to achieve complex messages using GWT i18n Messages interface
body: <p>I am trying to achieve the following string(s) format using GWT Messages but am not sure how to do it (or even if it can be done).</p>
  
  <p>I have a Messages method signature like this:</p>
  
  <p><code>String organizedMessage(String username, String date);</code></p>
  
  <p>I have 2 arguments: username, date. Sometimes the username is null and sometimes the date is null but they are never both null at the same time.</p>
  
  <p>Scenario #1: Username and Date both exist =
  "Organized by [username] on [date]"</p>
  
  <p>Scenario #2: Username exists but Date is null =
  "Organized by [username]</p>
  
  <p>Scenario #3: Username is null but date exists =
  "Organized on [date]"</p>
  
  <p>Can this be done with GWT Messages? Thanks in advance...</p>