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