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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 _plain_authentication(self, login, password, authz_id=b""):
 """SASL PLAIN authentication :param login: username :param password: clear password :return: True on success, False otherwise. """

        if isinstance(login, six.text_type):
            login = login.encode("utf-8")
        if isinstance(password, six.text_type):
            password = password.encode("utf-8")
        params = base64.b64encode(b'\0'.join([authz_id, login, password]))
        code, data = self.__send_command("AUTHENTICATE", [b"PLAIN", params])
        if code == "OK":
            return True
        return False