code: def get_entity_by_tag(self, tag):
          '''
          Get entity by tag
          tag is a string that is the tag of the Entity.
          '''
          matching_entities = list(filter(lambda entity: entity.get_tag() == tag,
                                          self._entities))
          if matching_entities:
              return matching_entities[0]
          else:
              return Nonf get_entity_by_tag(self, tag):
          '''
          Get entity by tag
          tag is a string that is the tag of the Entity.
          '''
          matching_entities = list(filter(lambda entity: entity.get_tag() == tag,
                                          self._entities))
          if matching_entities:
              return matching_entities[0]
          else:
              return None
docs: Get entity by tag
          tag is a string that is the tag of the Entity.