typedef struct
{
    CFIndex                             version;
    const char *                        className;
    CFRuntimeInitFunc                   init;
    CFRuntimeCopyFunc                   copy;
    CFRuntimeFinalizeFunc               finalize;
    CFRuntimeEqualFunc                  equal;
    CFRuntimeHashFunc                   hash;
    CFRuntimeCopyFormattingDescFunc     copyFormattingDesc;
    CFRuntimeCopyDebugDescFunc          copyDebugDesc;
    CFRuntimeReclaimFunc                reclaim;
    CFRuntimeRefCountFunc               refcount;

}   CFRuntimeClass;