public void AddCharacter(CharacterRow character)
        {
            if (character == null)
            {
                throw new ArgumentNullException(nameof(character));
            }

            if (character.Id == null)
            {
                return;
            }

            this.characters[character.Id] = character;
        }
 public static bool IsNullOrNone(this CharacterRow self)
 => self == null || self == CharacterRow.None;