code: public static List<String> getAllVariantKeysFromFixedVariants(Map<String, VariantSet> variants,
  			Map<String, String> fixedVariants) {
  
  		Map<String, VariantSet> tempVariants = new HashMap<>(variants);
  
  		if (fixedVariants != null) {
  
  			for (Entry<String, String> entry : fixedVariants.entrySet()) {
  				VariantSet variantSet = tempVariants.get(entry.getKey());
  				if (variantSet != null) {
  					String variantValue = variantSet.getDefaultVariant();
  					if (variantSet.contains(entry.getValue())) {
  						variantValue = entry.getValue();
  					}
  
  					VariantSet newVariantSet = new VariantSet(variantSet.getType(), variantValue,
  							Arrays.asList(variantValue));
  					tempVariants.put(variantSet.getType(), newVariantSet);
  				}
  			}
  		}
  
  		return getAllVariantKeys(tempVariants);
  	}
docs: Returns all variant keys from the map of variant set
  
  @param variants
  the map of variant set
  @param fixedVariants
  the fixed variant map
  @return all variant keys