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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 check_email_exists_by_subject(self, subject, match_recipient=None):
 """ Searches for Email by Subject. Returns True or False. Args: subject (str):
 Subject to search for. Kwargs: match_recipient (str) : Recipient to match exactly. (don't care if not specified) Returns: True - email found, False - email not found """

        # Select inbox to fetch the latest mail on server.
        self._mail.select("inbox")

        try:
            matches = self.__search_email_by_subject(subject, match_recipient)
            if len(matches) <= 0:
                return False
            else:
                return True
        except Exception as e:
            raise e