code: @Override
  	protected String initValuesImpl(final FieldCase c) {
  		double d = 0.0;
  		String v = source.initValues(c);
  		if (v != null && v.length() > 0) {
  			d = 0.0;
  			try {
  				Number n = format.parse(v);
  				d = n.doubleValue();
  			} catch (ParseException e) {
  				log.debug("Could not parse string " + v + " to a number; setting value 0.0");
  			}
  		}
  		d *= factor;
  		return format.format(d);
  	}
docs: Initializes the source constraint first. Then the source constraint's value is parsed with
  the format object of this constraint to a double number and this value is subsequently
  multiplied with the configurable factor. The multiplied value is finally formatted to a
  string using the the format object again and stored as a value.
  
  @return the value just generated