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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 posix_props(self, prop, in_group=False):
 """ Insert POSIX properties. Posix style properties are not as forgiving as Unicode properties. Case does matter, and whitespace and '-' and '_' will not be tolerated. """


        try:
            if self.is_bytes or not self.unicode:
                pattern = _uniprops.get_posix_property(
                    prop, (_uniprops.POSIX_BYTES if self.is_bytes else _uniprops.POSIX)
                )
            else:
                pattern = _uniprops.get_posix_property(prop, _uniprops.POSIX_UNICODE)
        except Exception:
            raise ValueError('Invalid POSIX property!')
        if not in_group and not pattern:  # pragma: no cover
            pattern = '^%s' % ('\x00-\xff' if self.is_bytes else _uniprops.UNICODE_RANGE)

        return [pattern]