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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 serialize(self, buf=None, lineLength=75, validate=True, behavior=None):
 """ Serialize to buf if it exists, otherwise return a string. Use self.behavior.serialize if behavior exists. """

        if not behavior:
            behavior = self.behavior

        if behavior:
            if DEBUG:
                logger.debug("serializing {0!s} with behavior {1!s}".format(self.name, behavior))
            return behavior.serialize(self, buf, lineLength, validate)
        else:
            if DEBUG:
                logger.debug("serializing {0!s} without behavior".format(self.name))
            return defaultSerialize(self, buf, lineLength)