def parse_value(self, stream):
        """
        Value ::= (SimpleValue | Set | Sequence) WSC UnitsExpression?
        """
        if self.has_sequence(stream):
            value = self.parse_sequence(stream)
        elif self.has_set(stream):
            value = self.parse_set(stream)
        else:
            value = self.parse_simple_value(stream)

        self.skip_whitespace_or_comment(stream)

        if self.has_units(stream):
            return Units(value, self.parse_units(stream))

        return value
Value ::= (SimpleValue | Set | Sequence) WSC UnitsExpression?