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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 get_smtp_header(self):
 """ Returns the SMTP formatted header of the line. :rtype: string :return: The SMTP header. """

        header = "From: %s\r\n" % self.get_sender()
        header += "To: %s\r\n" % ',\r\n '.join(self.get_to())
        header += "Cc: %s\r\n" % ',\r\n '.join(self.get_cc())
        header += "Bcc: %s\r\n" % ',\r\n '.join(self.get_bcc())
        header += "Subject: %s\r\n" % self.get_subject()
        return header