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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_interop_ns(self, interop_ns):
 """ Validate whether the specified Interop namespace exists in the WBEM server, by communicating with it. If the specified Interop namespace exists, this method sets the :attr:`interop_ns` property of this object to that namespace and returns. Otherwise, it raises an exception. Parameters: interop_ns (:term:`string`):
 Name of the Interop namespace to be validated. Raises: Exceptions raised by :class:`~pywbem.WBEMConnection`. """

        test_classname = 'CIM_Namespace'
        try:
            self._conn.EnumerateInstanceNames(test_classname,
                                              namespace=interop_ns)
        except CIMError as exc:
            # We tolerate it if the WBEM server does not implement this class,
            # as long as it does not return CIM_ERR_INVALID_NAMESPACE.
            if exc.status_code in (CIM_ERR_INVALID_CLASS,
                                   CIM_ERR_NOT_FOUND):
                pass
            else:
                raise
        self._interop_ns = interop_ns