static String readToString(String filename) {
        try {
            return Files.readString(Paths.get(filename), StandardCharsets.UTF_8);
        } catch (IOException e) {
            throw new UncheckedIOException(e);
        }
    }
An implementation of {@link SslProvider} that uses the {@link ConnectorConfig} to configure SSL.

@author bjorncs
container-core/src/main/java/com/yahoo/jdisc/http/ssl/impl/ConfiguredSslContextFactoryProvider.java