@Override public boolean equals(Object obj)
    {
        if (this == obj) return true;
        if (obj == null) return false;
        if (!(obj instanceof Sector91Version)) return false;
        Sector91Version other = (Sector91Version)obj;
        if (majorVersion() != other.majorVersion()) return false;
        if (month() != other.month()) return false;
        if (year() != other.year()) return false;
        if (minorVersion() != other.minorVersion()) return false;
        if (!letterSuffix.equals(other.letterSuffix)) return false;
        return true;
    }