code: def properties(self):
          
          properties = {'id': self._id,
                        'boundary': self._boundary}
          if 'name' in self._root.attrib:
              properties['name'] = self._root.get('name')
          if 'compartment' in self._root.attrib:
              properties['compartment'] = self._root.get('compartment')
  
          charge = self.charge
          if charge is not None:
              properties['charge'] = charge
  
          formula = self.formula
          if formula is not None:
              properties['formula'] = formula
  
          return properties
docs: All species properties as a dict