set self._all_merged_entities to the longest possible(wrapping)
        tokens including non-entity tokens

def _parse_all_merged_entities(self):
        """set self._all_merged_entities to the longest possible(wrapping)
        tokens including non-entity tokens
        """
        self._all_merged_entities = list(filterfalse(
            lambda token: self._is_wrapped(token, self.all_entities),
            self.all_entities))