ShExC: literalExclusion = '-' literal STEM_MARK?
            ShExJ: exclusions: [STRING|LiteralStem +]
                   literalStem: {stem:STRING}

def _literal_exclusions(self, stem: LiteralStemRange,
                            exclusions: List[ShExDocParser.LiteralExclusionContext]) -> None:
        """ ShExC: literalExclusion = '-' literal STEM_MARK?
            ShExJ: exclusions: [STRING|LiteralStem +]
                   literalStem: {stem:STRING}
        """
        for excl in exclusions:
            excl_literal_v = self.context.literal_to_ObjectLiteral(excl.literal()).value
            stem.exclusions.append(LiteralStem(excl_literal_v) if excl.STEM_MARK() else excl_literal_v)