title: Is It Possible to Deprecate Method Parameters in PHP?
body: <p>Lets say I have a method:</p>
  
  <pre><code>public function createFoo(Foo $foo, $isPremiumFoo=false);
  </code></pre>
  
  <p>In hindsight, it was a little silly to have that <code>$isPremiumFoo</code> flag argument hanging off the end. So we moved it into <code>Foo</code> and now I'd like to remove it from the method signature. But I don't want to do it all at once since this is a public method and is out in the wild being used. I'd like to <code>@deprecate</code> it to alert users to the fact that they should stop using it and then eventually remove it. Since you can't overload methods in PHP, how can I deprecate just that method argument and not the entire method?</p>