ParameterConverterFinder.java

private Iterable<Object[]> convert(final Iterable<Object[]> data) {
    List<Object[]> parameters = new ArrayList<>();
    for (Object[] args : data) {
        Object[] params = new Object[args.length];
        for (int i = 0; i < args.length; i++) {
            final Class<?> parameterClazz = method.getMethod()
                    .getParameterTypes()[i];
            params[i] = convertParameter(args[i], parameterClazz);
        }
        parameters.add(params);
    }
    return parameters;
}

private Object convertParameter(final Object parameter,
                                final Class<?> parameterClass) {
    return getParameterConverter(parameterClass)
            .map(converter -> converter.convert(parameter))
            .orElseThrow(() -> new NotFoundParameterGeneratorException("Cannot convert " + parameter + " to " + parameterClass));
}

private Optional<? extends ParameterConverter<Object, ?>> getParameterConverter(final Class<?> parameterClass) {
    return Optional.ofNullable(convertersByClass.get(parameterClass));
}