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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 _validate_pdf_file(self):
 """Validate that the pdf_path configuration is set and the referenced file exists. Exits the program with status 1 if validation fails. """

        if self['pdf_path'] is None:
            self._logger.error('--pdf argument must be set')
            sys.exit(1)
        if not os.path.exists(self['pdf_path']):
            self._logger.error('Cannot find PDF ' + self['pdf_path'])
            sys.exit(1)