} else if (RangeConstraint.NAME.equals(config.getConstraintName())) {
return new RangeConstraint();
} else if (NotMatchesConstraint.NAME.equals(config.getConstraintName())) {
return new NotMatchesConstraint();
}else if (MatchesConstraint.NAME.equals(config.getConstraintName())) {
return new MatchesConstraint();
}else if (InvalidFieldConstraint.NAME.equals(config.getConstraintName())) {
return new InvalidFieldConstraint();
} else {
throw new IllegalArgumentException("Constraint unknown: " + config.getConstraintName());
}