def change_message_visibility(self, queue, receipt_handle,
                                  visibility_timeout, callback=None):
        """
        Extends the read lock timeout for the specified message from
        the specified queue to the specified value.

        :type queue: A :class:`boto.sqs.queue.Queue` object
        :param queue: The Queue from which messages are read.
        
        :type receipt_handle: str
        :param queue: The receipt handle associated with the message whose
                      visibility timeout will be changed.
        
        :type visibility_timeout: int
        :param visibility_timeout: The new value of the message's visibility
                                   timeout in seconds.
        """
        params = {'ReceiptHandle' : receipt_handle,
                  'VisibilityTimeout' : visibility_timeout}
        return self.get_status('ChangeMessageVisibility', params, queue.id, callback=callback)
Extends the read lock timeout for the specified message from
        the specified queue to the specified value.

        :type queue: A :class:`boto.sqs.queue.Queue` object
        :param queue: The Queue from which messages are read.
        
        :type receipt_handle: str
        :param queue: The receipt handle associated with the message whose
                      visibility timeout will be changed.
        
        :type visibility_timeout: int
        :param visibility_timeout: The new value of the message's visibility
                                   timeout in seconds.