GetGroup.
        [Preview API] Get a group by its descriptor.
        :param str group_descriptor: The descriptor of the desired graph group.
        :rtype: :class:`<GraphGroup> <azure.devops.v5_0.graph.models.GraphGroup>`

def get_group(self, group_descriptor):
        """GetGroup.
        [Preview API] Get a group by its descriptor.
        :param str group_descriptor: The descriptor of the desired graph group.
        :rtype: :class:`<GraphGroup> <azure.devops.v5_0.graph.models.GraphGroup>`
        """
        route_values = {}
        if group_descriptor is not None:
            route_values['groupDescriptor'] = self._serialize.url('group_descriptor', group_descriptor, 'str')
        response = self._send(http_method='GET',
                              location_id='ebbe6af8-0b91-4c13-8cf1-777c14858188',
                              version='5.0-preview.1',
                              route_values=route_values)
        return self._deserialize('GraphGroup', response)