title: multiple classes with same methods - best pattern
body: <p>I have a few classes in my current project where validation of Email/Website addresses is necessary.  The methods to do that are all the same.  </p>
  
  <p>I wondered what's the best way to implement this, so I don't need to have these methods copy pasted everywhere?</p>
  
  <p>The classes themselves are not necessarily related, they only have those validation methods in common.</p>