title: What does "this" mean in a static method declaration?
body: <p>I've seen some code that uses the keyword <code>this</code> in the function parameter declaration. For example:</p>
  
  <pre><code>public static Object SomeMethod( this Object blah, bool blahblah)
  </code></pre>
  
  <p>What does the word <code>this</code> mean in that context?</p>