带有任意Python对象的Amazon SQS消息？

所以,我正在尝试使用SQS在两个EC2实例之间传递Python对象.这是我失败的尝试:

import boto.sqs
from boto.sqs.message import Message

class UserInput(Message):
    def set_email(self, email):
        self.email = email
    def set_data(self, data):
        self.data = data
    def get_email(self):
        return self.email
    def get_data(self):
        return self.data

conn = boto.sqs.connect_to_region('us-west-2')
q = conn.create_queue('user_input_queue')
q.set_message_class(UserInput)
m = UserInput()
m.set_email('something@something.com')
m.set_data({'foo': 'bar'})
q.write(m)

它会返回一条错误消息The request must contain the parameter MessageBody.实际上,该教程告诉我们m.set_body('something')在将消息写入队列之前要做的事情.但是这里我没有传递字符串,我想传递一个UserInput类的实例.那么,MessageBody应该是什么？我已经阅读了文档并且他们说了

The constructor for the Message class must accept a keyword parameter “body” which represents the content or body of the message. The format of this parameter will depend on the behavior of the particular Message subclass. For example, if the Message subclass provides dictionary-like behavior to the user the body passed to the constructor should be a dict-like object that can be used to populate the initial state of the message.

我想我的问题的答案可能在那一段,但我无法理解.任何人都可以提供具体的代码示例来说明他们在谈论什么吗？