code: public void deactivateAll() {
          for (String scheme : new String[] {"http", "https"}) {
              InetSocketAddress originalProxy = originalProxies.remove(scheme);
              if (originalProxy != null) {
                  System.setProperty(scheme + ".proxyHost", originalProxy.getHostName());
                  System.setProperty(scheme + ".proxyPort", Integer.toString(originalProxy.getPort()));
              } else {
                  System.clearProperty(scheme + ".proxyHost");
                  System.clearProperty(scheme + ".proxyPort");
              }
          }
  
          if (originalNonProxyHosts.isEmpty()) {
              System.clearProperty("http.nonProxyHosts");
          } else {
              System.setProperty("http.nonProxyHosts", Joiner.on('|').join(originalNonProxyHosts));
          }
          originalNonProxyHosts.clear();
      }
docs: Deactivates all proxy overrides restoring the pre-existing proxy settings if any.