All reaction properties as a dict

def properties(self):
        """All reaction properties as a dict"""
        properties = {'id': self._id,
                      'reversible': self._rev,
                      'equation': self._equation}
        if 'name' in self._root.attrib:
            properties['name'] = self._root.get('name')
        if self._lower_flux is not None:
            properties['lower_flux'] = self._lower_flux
        if self._upper_flux is not None:
            properties['upper_flux'] = self._upper_flux

        return properties