'Create an instance of InstructorTask.'

@classmethod
def create(cls, course_id, task_type, task_key, task_input, requester):

    task_id = str(uuid4())
    json_task_input = json.dumps(task_input)
    if (len(json_task_input) > 255):
        fmt = 'Task    input    longer    than    255:    "{input}"    for    "{task}"    of    "{course}"'
        msg = fmt.format(input=json_task_input, task=task_type, course=course_id)
        raise ValueError(msg)
    instructor_task = cls(course_id=course_id, task_type=task_type, task_id=task_id, task_key=task_key, task_input=json_task_input, task_state=QUEUING, requester=requester)
    instructor_task.save_now()
    return instructor_task
