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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 set_filter(self, value, name=constants.STRING_FILTER, descriptor=constants.STRING_FILTER):
 """Set a filter on the endpoint. Only one filter can be applied to an endpoint. :param value: The filter to apply to the endpoint. Set to None for a NULL filter. :type value: bytes or str or None :param name: The name of the filter. This will be encoded as an AMQP Symbol. By default this is set to b'apache.org:selector-filter:string'. :type name: bytes :param descriptor: The descriptor used if the filter is to be encoded as a described value. This will be encoded as an AMQP Symbol. By default this is set to b'apache.org:selector-filter:string'. Set to None if the filter should not be encoded as a described value. :type descriptor: bytes or None """

        value = value.encode(self._encoding) if isinstance(value, six.text_type) else value
        filter_set = c_uamqp.dict_value()
        filter_key = c_uamqp.symbol_value(name)
        filter_value = utils.data_factory(value, encoding=self._encoding)
        if value is not None and descriptor is not None:
            descriptor = c_uamqp.symbol_value(descriptor)
            filter_value = c_uamqp.described_value(descriptor, filter_value)

        filter_set[filter_key] = filter_value
        self._address.filter_set = filter_set