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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 _get_subparsers(self, dest):
 """Get named subparsers."""

        if not self._subparsers:
            self._subparsers = self.parser.add_subparsers(dest=dest)
        elif self._subparsers.dest != dest:
            raise KeyError(
                "Subparser names mismatch. You can only create one subcommand.")
        return self._subparsers