title: respondsToSelector with different argument types in selector
body: <p>Suppose we have different Object which have the same method name but with differet argument types like: <code>getMethod:(NSNumber*)aNumber</code> and <code>getMethod:(NSString*)aString</code>.</p>
  
  <p>How to check with respondsToSelector or through other way, if an object responds to the selector with particular argument type, something like this:</p>
  
  <pre><code>[myObjectA respondsToSelector:@selector(getMethod:(NSNumber*))]
  </code></pre>
  
  <p>How do you do this?
  Thanks.</p>