@classmethod
def check(cls, identifier):
    """
        Given an identifier, this should check whether the identifier is
        still considered valid or not - or whether it cannot make that
        assumption. 

        This should return one of the three following:

            ScanProcess.IS_VALID
                If the identifier is still active and valid, this should
                be returned

            ScanProcess.NOT_VALID
                If the identifier should no longer be considered within
                fracture this should be returned

            ScanProcess.UNKNOWN
                If the identifier is not digestable by this process for
                any reason this should be returned.

        :return: int 
        """
    return cls.UNKNOWN
