@Override
public boolean equals(Object obj) {
	if (obj == null) {
		return false;
	}
	if (getClass() != obj.getClass()) {
		return false;
	}
	final boxState other = (boxState) obj;
	if (this.toFill != other.toFill &&
		(this.toFill == null || !this.toFill.equals(other.toFill))) {
		return false;
	}
	if (this.toPut != other.toPut && (this.toPut == null || !this.toPut.equals(other.toPut))) {
		return false;
	}
	return true;
}