class UnitChange implements NormalizationRule {

  public UnitChange(String field, double multiplier) {
    ArgumentChecker.notNull(field, "Field name");
    _fields = ImmutableSet.of(field);
    _multiplier = multiplier;        
  }

  public  UnitChange(String field, double multiplier);
  public  UnitChange(Set<String> fields, double multiplier);
  public  UnitChange(double multiplier, String... fields);

}