class DefaultEmailSenderProvider implements EmailSenderProvider {

    @Override
    public Optional<TemplatedEmailSender> lookupTemplatedEmailSenderFor(final String providerType) {
        assertValidProviderTypeArgument(providerType);
        return Optional.ofNullable(registeredTemplatedEmailSenders.get(providerType));
    }

      DefaultEmailSenderProvider(final List<SimpleEmailSenderRegistry> simpleEmailSenderRegistries,
                               final List<TemplatedEmailSenderRegistry> templatedEmailSenderRegistries);

}