code: def get_entity(self,entity_id):
            
          entity_node = self.map_entity_id_to_node.get(entity_id)
          if entity_node is not None:
              return Centity(node=entity_node,type=self.type)
          else:
              for entity_node in self.__get_entity_nodes():
                  if self.type == 'NAF': 
                      label_id = 'id'
                  elif self.type == 'KAF': 
                      label_id = 'eid'
                  if entity_node.get(label_id) == entity_id:
                      return Centity(node=entity_node, type=self.type)                                                                
              return None
docs: Returns the entity object for the given entity identifier
          @type entity_id: string
          @param entity_id: the token identifier
          @rtype: L{Centity}
          @return: the entity object