code: public boolean hasSameDefaultVariant(VariantSet obj) {
  
  		return (this.defaultVariant == null && obj.defaultVariant == null)
  				|| (this.defaultVariant != null && this.defaultVariant.equals(obj.defaultVariant));
  	}
docs: Returns true of the variantSet passed in parameter has the same default
  value
  
  @param obj
  the variantSet to test
  @return true of the variantSet passed in parameter has the same default
  value