public Subclass withClientSideMonitoringConfigurationProvider(
            CsmConfigurationProvider csmConfig) {
        setClientSideMonitoringConfigurationProvider(csmConfig);
        return getSubclass();
    }
Request handlers are copied to a new list to avoid mutation, if no request handlers are
provided to the builder we supply an empty list.
aws-java-sdk-core/src/main/java/com/amazonaws/client/builder/AwsClientBuilder.java