UpdateAgentPool.
        [Preview API] Update properties on an agent pool
        :param :class:`<TaskAgentPool> <azure.devops.v5_1.task_agent.models.TaskAgentPool>` pool: Updated agent pool details
        :param int pool_id: The agent pool to update
        :rtype: :class:`<TaskAgentPool> <azure.devops.v5_1.task-agent.models.TaskAgentPool>`

def update_agent_pool(self, pool, pool_id):
        """UpdateAgentPool.
        [Preview API] Update properties on an agent pool
        :param :class:`<TaskAgentPool> <azure.devops.v5_1.task_agent.models.TaskAgentPool>` pool: Updated agent pool details
        :param int pool_id: The agent pool to update
        :rtype: :class:`<TaskAgentPool> <azure.devops.v5_1.task-agent.models.TaskAgentPool>`
        """
        route_values = {}
        if pool_id is not None:
            route_values['poolId'] = self._serialize.url('pool_id', pool_id, 'int')
        content = self._serialize.body(pool, 'TaskAgentPool')
        response = self._send(http_method='PATCH',
                              location_id='a8c47e17-4d56-4a56-92bb-de7ea7dc65be',
                              version='5.1-preview.1',
                              route_values=route_values,
                              content=content)
        return self._deserialize('TaskAgentPool', response)