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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def endheaders(self, message_body=None):
 """Indicate that the last header line has been sent to the server. This method sends the request to the server. The optional message_body argument can be used to pass a message body associated with the request. The message body will be sent in the same packet as the message headers if it is a string, otherwise it is sent as a separate packet. """

        if self.__state == _CS_REQ_STARTED:
            self.__state = _CS_REQ_SENT
        else:
            raise CannotSendHeader()
        self._send_output(message_body)