code: func (c *client) CreateIfNotExists(ctx context.Context, entity DomainObject) error {
  	return c.createOrUpsert(ctx, nil, entity, c.connector.CreateIfNotExists)
  }
docs: // CreateIfNotExists creates a row, but only if it does not exist. The entity
  // provided must contain values for all components of its primary key for the
  // operation to succeed.