title: iOS 13 get application statusBar crash
body: <p>only crash on beta2 and beta 3 when call code like this,:</p>
  
  <pre><code>[application valueForKeyPath:@"statusBar"]
  </code></pre>
  
  <p>some can help me? i call this method to get phone's network status.
  the whole code like this:</p>
  
  <pre class="lang-c prettyprint-override"><code>if (![self isIPhoneX]) {
          if ([[application valueForKeyPath:@"_statusBar"] isKindOfClass:NSClassFromString(@"UIStatusBar_Modern")]) {
              children = [[[[application valueForKeyPath:@"_statusBar"] valueForKeyPath:@"_statusBar"] valueForKeyPath:@"foregroundView"] subviews];
          } else {
              children = [[[application valueForKeyPath:@"_statusBar"] valueForKeyPath:@"foregroundView"] subviews];
          }
          Class expectClass = NSClassFromString(@"UIStatusBarDataNetworkItemView");
          for (id child in children) {
              if ([child isKindOfClass:expectClass]) {
                  int netType = [[child valueForKeyPath:@"dataNetworkType"] intValue];
                  switch (netType) {
                      case 0: state  = @"";break;
                      case 1: state  = @"2g";break;
                      case 2: state  = @"3g";break;
                      case 3: state  = @"4g";break;
                      case 5: state  = @"wifi";break;
                      default: state = @"";break;
                  } /* switch */
              }
          }
      } else {
          id statusBar = [application valueForKeyPath:@"statusBar"];
          id statusBarView = [statusBar valueForKeyPath:@"statusBar"];
          UIView *foregroundView = [statusBarView valueForKeyPath:@"foregroundView"];
          children = [[foregroundView subviews][2] subviews];
          for (id child in children) {
              if ([child isKindOfClass:NSClassFromString(@"_UIStatusBarWifiSignalView")]) {
                  state  = @"wifi";  
              }else if ([child isKindOfClass:NSClassFromString(@"_UIStatusBarStringView")]) {
                  NSString *str = [child valueForKeyPath:@"_originalText"]; 
                  if ([str isEqualToString:@"4G"]) {
                      state  = @"4g";  
                  }else if([str isEqualToString:@"3G"]){
                      state  = @"3g"; 
                  } else{
                      state  = @"2g"; 
                  }
              }
          }
      }
  </code></pre>
  
  <p>I install iOS 13 open beta version and every thing runs good except some label showing ...,but i receive crash when online beta2 and beta3 version.</p>