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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def __log_overview_errors(self):
 """ Show info about sources files of stored routines that were not loaded successfully. """

        if self.error_file_names:
            self._io.warning('Routines in the files below are not loaded:')
            self._io.listing(sorted(self.error_file_names))