* <li>WP_PROXY_USERNAME - Proxy username, if it requires authentication.</li>
* <li>WP_PROXY_PASSWORD - Proxy password, if it requires authentication.</li>
* <li>WP_PROXY_BYPASS_HOSTS - Will prevent the hosts in this list from going through the proxy.
* <li>WP_PROXY_USERNAME - Proxy username, if it requires authentication.</li>
* <li>WP_PROXY_PASSWORD - Proxy password, if it requires authentication.</li>
* <li>WP_PROXY_BYPASS_HOSTS - Will prevent the hosts in this list from going through the proxy.