8. A non-transitory computer readable medium including instructions for a comparative testing tool that, when executed by a processing device cause the processing device to perform a method, comprising: receiving multiple program code files; identifying, by the processing device using a problem collection generator executed by the processing device, collections of problem objects present in each of the multiple program code files based on an object oriented model that classifies errors in the multiple program code files based on a class and behavior, wherein the problem collection generator is configured to determine pointers for the problem objects that indicate a location of the errors in the multiple program code files, wherein each problem object in the collections of problem objects comprises a class and a pointer to a location of an error in one of the multiple program code files, the class classifying the error in one of the multiple program code files; comparing, by the processing device using a set of comparison engines executed by the processing device, respective internal structures of the multiple program code files, pairs of the problem objects from the collections; and determining which of the problem objects have been resolved and which of the problem objects are new.
8. A non-transitory computer readable medium including instructions for a comparative testing tool that, when executed by a processing device cause the processing device to perform a method, comprising: receiving multiple program code files; identifying, by the processing device using a problem collection generator executed by the processing device, collections of problem objects present in each of the multiple program code files based on an object oriented model that classifies errors in the multiple program code files based on a class and behavior, wherein the problem collection generator is configured to determine pointers for the problem objects that indicate a location of the errors in the multiple program code files, wherein each problem object in the collections of problem objects comprises a class and a pointer to a location of an error in one of the multiple program code files, the class classifying the error in one of the multiple program code files; comparing, by the processing device using a set of comparison engines executed by the processing device, respective internal structures of the multiple program code files, pairs of the problem objects from the collections; and determining which of the problem objects have been resolved and which of the problem objects are new. 10. The non-transitory computer readable medium of claim 8 , wherein the set of comparison engines are configured to compare a specific class of the problem objects.