public Optional<Protocol> getProtocol() {
        return Optional.ofNullable(protocol);
    }
Returns the protocol (HTTP or HTTPS) to use when connecting through proxy.
<p>
The default configuration is to use HTTPS for all requests for increased security.
<p>

@return The protocol to use when connecting through proxy.
aws-java-sdk-opensdk/src/main/java/com/amazonaws/opensdk/config/ProxyConfiguration.java