GetReviews.
        [Preview API] Returns a list of reviews associated with an extension
        :param str publisher_name: Name of the publisher who published the extension
        :param str extension_name: Name of the extension
        :param int count: Number of reviews to retrieve (defaults to 5)
        :param str filter_options: FilterOptions to filter out empty reviews etcetera, defaults to none
        :param datetime before_date: Use if you want to fetch reviews older than the specified date, defaults to null
        :param datetime after_date: Use if you want to fetch reviews newer than the specified date, defaults to null
        :rtype: :class:`<ReviewsResult> <azure.devops.v5_1.gallery.models.ReviewsResult>`

def get_reviews(self, publisher_name, extension_name, count=None, filter_options=None, before_date=None, after_date=None):
        """GetReviews.
        [Preview API] Returns a list of reviews associated with an extension
        :param str publisher_name: Name of the publisher who published the extension
        :param str extension_name: Name of the extension
        :param int count: Number of reviews to retrieve (defaults to 5)
        :param str filter_options: FilterOptions to filter out empty reviews etcetera, defaults to none
        :param datetime before_date: Use if you want to fetch reviews older than the specified date, defaults to null
        :param datetime after_date: Use if you want to fetch reviews newer than the specified date, defaults to null
        :rtype: :class:`<ReviewsResult> <azure.devops.v5_1.gallery.models.ReviewsResult>`
        """
        route_values = {}
        if publisher_name is not None:
            route_values['publisherName'] = self._serialize.url('publisher_name', publisher_name, 'str')
        if extension_name is not None:
            route_values['extensionName'] = self._serialize.url('extension_name', extension_name, 'str')
        query_parameters = {}
        if count is not None:
            query_parameters['count'] = self._serialize.query('count', count, 'int')
        if filter_options is not None:
            query_parameters['filterOptions'] = self._serialize.query('filter_options', filter_options, 'str')
        if before_date is not None:
            query_parameters['beforeDate'] = self._serialize.query('before_date', before_date, 'iso-8601')
        if after_date is not None:
            query_parameters['afterDate'] = self._serialize.query('after_date', after_date, 'iso-8601')
        response = self._send(http_method='GET',
                              location_id='5b3f819f-f247-42ad-8c00-dd9ab9ab246d',
                              version='5.1-preview.1',
                              route_values=route_values,
                              query_parameters=query_parameters)
        return self._deserialize('ReviewsResult', response)