code: public SearchKey asSearchKey() {
  		Constant[] vals = new Constant[ranges.length];
  		for (int i = 0; i < vals.length; i++)
  			vals[i] = ranges[i].asConstant();
  		return new SearchKey(vals);
  	}
docs: Converts this range into a {@link SearchKey}. We expect the caller will
  call {@link #isSingleValue()} before calling this method.
  
  @return a SearchKey represents the range