snaker-core/src/main/java/org/snaker/engine/core/TaskService.java
public Task take(String taskId, String operator) {
		Task task = access().getTask(taskId);
		AssertHelper.notNull(task, "指定的任务[id=" + taskId + "]不存在");
		if(!isAllowed(task, operator)) {
			throw new SnakerException("当前参与者[" + operator + "]不允许提取任务[taskId=" + taskId + "]");
		}
		task.setOperator(operator);
		task.setFinishTime(DateHelper.getTime());
		access().updateTask(task);
		return task;
	}
public Task take(String taskId, String operator) {
		Task task = access().getTask(taskId);
		AssertHelper.notNull(task, "指定的任务[id=" + taskId + "]不存在");
		if(!isAllowed(task, operator)) {
			throw new SnakerException("当前参与者[" + operator + "]不允许提取任务[taskId=" + taskId + "]");
		}
		task.setOperator(operator);
		task.setFinishTime(DateHelper.getTime());
		access().updateTask(task);
		return task;
	}
提取指定任务，设置完成时间及操作人，状态不改变