def get_student_activities(self, student, lesson, task_idx):
from model import StudentActivity, EXPECTED_UPPER_BOUND
query = StudentActivity.all()
query = query.filter('student =', student).filter('lesson =', lesson).filter('task_idx =', task_idx)
query.order('timestamp')
activities = []
for activity in query.fetch(EXPECTED_UPPER_BOUND):
activities.append(activity.toDict())
return activities
