title: iOS Theos Hook and set ivar/property
body: <p>I have the following class that I am hooking, I am trying to figure out how to hook and set m_proxyPort. I can read it without issue, but how about if I want to change it?</p>
  
  <p>There is a setter for the 3 NSString ivars, but theres no setter for m_proxyPort, would like to know if there is a way to set that ivar?</p>
  
  <pre><code>@interface DDURLProtocol : NSURLProtocol &lt;NSURLAuthenticationChallengeSender, DDURLProtocolHttpAdapterDelegate&gt;
  {
      int m_proxyPort;
      NSString *_proxyHost;
      NSString *_proxyUsername;
      NSString *_proxyPassword;
  }
  
  
  %hook DDURLProtocol
  
  - (void) check 
  {
     [self setProxyHost:@"127.0.0.1"];
     int pp = MSHookIvar&lt;int&gt;(self, "m_proxyPort");
     NSLog(@"proxyPort: %d", pp);
     // How to set m_proxyPort????
  }
  
  
  %end
  </code></pre>