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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 __parse_email_to_employer_stream(self, stream):
 """Parse email to employer stream. The stream contains a list of email addresses and their employers. Each line has an email address and a organization name separated by tabs. Optionally, the date when the identity withdrew from the organization can be included followed by a '<' character. Comment lines start with the hash character (#). Example: # List of enrollments jsmith@example.com Example Company # John Smith jdoe@example.com Example Company # John Doe jsmith@example.com Bitergia < 2015-01-01 # John Smith - Bitergia """

        if not stream:
            return

        f = self.__parse_email_to_employer_line

        for rol in self.__parse_stream(stream, f):
            email = rol[0]
            org = rol[1]
            rol_date = rol[2]

            if org not in self.__raw_orgs:
                self.__raw_orgs[org] = []

            if email not in self.__raw_identities:
                self.__raw_identities[email] = [(org, rol_date)]
            else:
                self.__raw_identities[email].append((org, rol_date))