@Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Field other = (Field) obj;
        if (field == null) {
            if (other.field != null)
                return false;
        }
        else if (!field.equals(other.field))
            return false;
        if (rename == null) {
            if (other.rename != null)
                return false;
        }
        else if (!rename.equals(other.rename))
            return false;
        return true;
    }