title: Unable to find enum descriptor PBFieldDescriptorProto_Label while unit testing
body: <p>After adding the GoogleCast framework to the unit test target I'm getting the following exception right before the tests start to run. Apart from that the SDK is fully functional. I'd appreciate any ideas!</p>
  
  <pre><code>2014-02-25 18:03:08.475 otest[3786:303] Unknown Device Type. Using UIUserInterfaceIdiomPhone based on screen size
  2014-02-25 18:03:08.593 otest[3786:303] *** Assertion failure in -[GCKPB_PBFieldDescriptor initWithFieldDescription:rootClass:], /Volumes/BuildData/pulse-data/agents/wpye22.hot/recipes/415961027/base/googlemac/iPhone/Chromecast/SDKv2/Protos/../../../../ThirdParty/ProtocolBuffers/objectivec/Classes/PBDescriptor.m:409
  2014-02-25 18:03:08.596 otest[3786:303] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Unable to find enum descriptor PBFieldDescriptorProto_Label'
  *** First throw call stack:
  (
      0   CoreFoundation                      0x00b1d5e4 __exceptionPreprocess + 180
      1   libobjc.A.dylib                     0x007958b6 objc_exception_throw + 44
      2   CoreFoundation                      0x00b1d448 +[NSException raise:format:arguments:] + 136
      3   Foundation                          0x00010fee -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 116
      4   UnitTests                           0x077205dd -[GCKPB_PBFieldDescriptor initWithFieldDescription:rootClass:] + 1640
      5   UnitTests                           0x0771f52c +[GCKPB_PBDescriptor allocDescriptorForClass:rootClass:fields:fieldCount:enums:enumCount:ranges:rangeCount:storageSize:wireFormat:] + 173
      6   UnitTests                           0x076e550f +[GCKPB_PBFieldDescriptorProto descriptor] + 179
      7   UnitTests                           0x077226b2 +[GCKPB_PBGeneratedMessage initialize] + 100
      8   libobjc.A.dylib                     0x00796275 _class_initialize + 599
      9   libobjc.A.dylib                     0x0079d0f1 lookUpImpOrForward + 158
      10  libobjc.A.dylib                     0x0079d04e _class_lookupMethodAndLoadCache3 + 55
      11  libobjc.A.dylib                     0x007a512f objc_msgSend + 139
      12  SenTestingKit                       0x201086c6 +[NSObject(SenTestRuntimeUtilities) senIsASuperclassOfClass:] + 74
      13  SenTestingKit                       0x2010879e +[NSObject(SenTestRuntimeUtilities) senAllSubclasses] + 154
      14  SenTestingKit                       0x20106fa0 +[SenTestSuite updateCache] + 42
      15  SenTestingKit                       0x201071cf +[SenTestSuite suiteForBundleCache] + 93
      16  SenTestingKit                       0x20107241 +[SenTestSuite testSuiteForBundlePath:] + 101
      17  SenTestingKit                       0x201061fb +[SenTestProbe specifiedTestSuite] + 294
      18  SenTestingKit                       0x20106467 +[SenTestProbe runTests:] + 177
      19  libobjc.A.dylib                     0x007a7737 +[NSObject performSelector:withObject:] + 70
      20  otest                               0x00002372 otest + 4978
      21  otest                               0x000025c4 otest + 5572
      22  otest                               0x000026a5 otest + 5797
      23  otest                               0x00002031 otest + 4145
      24  libdyld.dylib                       0x0165570d start + 1
  )
  libc++abi.dylib: terminating with uncaught exception of type NSException
  </code></pre>