ConfigEntityStorage::save

public ConfigEntityStorage::save(EntityInterface $entity)

public function save(EntityInterface $entity) {
  // Configuration entity IDs are strings, and '0' is a valid ID.
  $id = $entity->id();
  if ($id === NULL || $id === '') {
    throw new EntityMalformedException('The entity does not have an ID.');
  }

  // Check the configuration entity ID length.
  // @see \Drupal\Core\Config\Entity\ConfigEntityStorage::MAX_ID_LENGTH
  // @todo Consider moving this to a protected method on the parent class, and
  //   abstracting it for all entity types.
  if (strlen($entity->get($this->idKey)) > self::MAX_ID_LENGTH) {
    throw new ConfigEntityIdLengthException("Configuration entity ID {$entity->get($this->idKey)} exceeds maximum allowed length of " . self::MAX_ID_LENGTH . " characters.");
  }

  return parent::save($entity);
}