def object
      @object ||= JSON.parse(body)
    rescue => error
      raise InvalidObjectError.new(error.to_s)
    end
def object
      @object ||= JSON.parse(body)
    rescue => error
      raise InvalidObjectError.new(error.to_s)
    end
@api
 @param [Queue] queue
 @param [String] id
 @param [String] handle
 @param [String] body
 @param [Hash] attributes
 The deserialized object in the message. This method is used to retrieve
 the contents that Queue#post_message placed there.

 @example

   queue.post_message([1,2,3])
   queue.retrieve.object == [1,2,3]