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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 after(self, after):
 """ Sets the after of this EnrollmentIdentities. ID :param after: The after of this EnrollmentIdentities. :type: str """

        if after is None:
            raise ValueError("Invalid value for `after`, must not be `None`")
        if after is not None and not re.search('^[A-Za-z0-9]{32}', after):
            raise ValueError("Invalid value for `after`, must be a follow pattern or equal to `/^[A-Za-z0-9]{32}/`")

        self._after = after