:return: a table containing taskid=>Task pairs

def get_all_tasks(self, course):
        """
        :return: a table containing taskid=>Task pairs
        """
        tasks = self.get_readable_tasks(course)
        output = {}
        for task in tasks:
            try:
                output[task] = self.get_task(course, task)
            except:
                pass
        return output