So as written above, this test will probably fail if I don't have the 6.0 or 6.1 SDKs installed, right?

We want to make sure xctool's test suite runs even if only the latest iOS SDK is installed.  Anyone who has Xcode 5 installed is guaranteed to have the iOS 7.0 SDK, but they may not have the 6.0 or 6.1 SDKs installed.  If we want to test the 6.0 or 6.1 paths, we have to fake it.

You could do something like the following to make `dictionaryWithContentsOfFile:` return the right stuff even if the SystemVersion.plist file isn't there --

```
  [Swizzler whileSwizzlingSelector:@selector(dictionaryWithContentsOfFile:)
                          forClass:[NSDictionary class]
                         withBlock:
   ^(id self, SEL cmd, NSString *path) {
     return @{@"ProductBuildVersion" : @"10A403",
              @"ProductVersion" : @"6.0"};
   }
                          runBlock:
   ^{
     assertThat(GetSDKVersionString(@"6.0"), equalTo(@"iPhone Simulator (external launch) , iPhone OS 6.0 (unknown/10A403)"));
   }];

```