title: WCF service design - new method or a filter
body: <p>I have a WCF service that returns phone numbers given an identifier. <code>[GetPhoneNumbersByIdentifier]</code></p>
  
  <p>I have another set of tables that stores the history of all phone number changes.</p>
  
  <p>There is a requirement to bring back historical phone numbers when a consumer requests for it. </p>
  
  <p>So shall I add a switch in my <code>GetPhoneNumbersByIdentifier [Bool GetHistory =&gt; True/False]</code></p>
  
  <p>Or should I create a new method - <code>GetAllPhoneNumbersByIdentifier</code>?</p>