SF bug #855317: unittest: 5.3.9 Getting Extended Error Information

The example code did not work and could not easily be made to work.
Since the docs were already complex and the feature was not used
(it took two years for the errors to surface), we decided to dedocument
it entirely, leaving unittest cleaner than before.

Doc/lib/libunittest.tex

@@ -900,45 +900,3 @@ either by subclassing or assignment on an instance:
   No methods on the resulting object are needed.  The default value is
   the \class{TestSuite} class.
 \end{memberdesc}
-
-
-\subsection{Getting Extended Error Information
-            \label{unittest-error-info}}
-
-Some applications can make use of more error information (for example,
-an integrated development environment, or IDE).  Such an application
-can retrieve supplemental information about errors and failures by
-using an alternate \class{TestResult} implementation, and extending
-the \method{defaultTestResult()} method of the \class{TestCase} class
-to provide it.
-
-Here is a brief example of a \class{TestResult} subclass which stores
-the actual exception and traceback objects.  (Be aware that storing
-traceback objects can cause a great deal of memory not to be reclaimed
-when it otherwise would be, which can have effects that affect the
-behavior of the tests.)
-
-\begin{verbatim}
-import unittest
-
-class MyTestCase(unittest.TestCase):
-    def defaultTestResult(self):
-        return MyTestResult()
-
-class MyTestResult(unittest.TestResult):
-    def __init__(self):
-        self.errors_tb = []
-        self.failures_tb = []
-
-    def addError(self, test, err):
-        self.errors_tb.append((test, err))
-        unittest.TestResult.addError(self, test, err)
-
-    def addFailure(self, test, err):
-        self.failures_tb.append((test, err))
-        unittest.TestResult.addFailure(self, test, err)
-\end{verbatim}
-
-Tests written using \class{MyTestCase} as the base class, instead of
-\class{TestCase}, will allow tools to extract additional information
-from the results object.