AddDeploymentGroup.
        [Preview API] Create a deployment group.
        :param :class:`<DeploymentGroupCreateParameter> <azure.devops.v5_1.task_agent.models.DeploymentGroupCreateParameter>` deployment_group: Deployment group to create.
        :param str project: Project ID or project name
        :rtype: :class:`<DeploymentGroup> <azure.devops.v5_1.task-agent.models.DeploymentGroup>`

def add_deployment_group(self, deployment_group, project):
        """AddDeploymentGroup.
        [Preview API] Create a deployment group.
        :param :class:`<DeploymentGroupCreateParameter> <azure.devops.v5_1.task_agent.models.DeploymentGroupCreateParameter>` deployment_group: Deployment group to create.
        :param str project: Project ID or project name
        :rtype: :class:`<DeploymentGroup> <azure.devops.v5_1.task-agent.models.DeploymentGroup>`
        """
        route_values = {}
        if project is not None:
            route_values['project'] = self._serialize.url('project', project, 'str')
        content = self._serialize.body(deployment_group, 'DeploymentGroupCreateParameter')
        response = self._send(http_method='POST',
                              location_id='083c4d89-ab35-45af-aa11-7cf66895c53e',
                              version='5.1-preview.1',
                              route_values=route_values,
                              content=content)
        return self._deserialize('DeploymentGroup', response)