@Internal
    protected HttpClientConnectionOperator createConnectionOperator(
            final SchemePortResolver schemePortResolver,
            final DnsResolver dnsResolver,
            final TlsSocketStrategy tlsSocketStrategy) {
        return new DefaultHttpClientConnectionOperator(schemePortResolver, dnsResolver,
                RegistryBuilder.<TlsSocketStrategy>create()
                        .register(URIScheme.HTTPS.id, tlsSocketStrategy)
                        .build());
    }
Use system properties when creating and configuring default
implementations.

@return this instance.
httpclient5/src/main/java/org/apache/hc/client5/http/impl/io/PoolingHttpClientConnectionManagerBuilder.java