code: protected synchronized void setVirtualHost(VirtualHost virtualHost) {
          this.virtualHost = virtualHost;
          if (!activeContextRoots.isEmpty()) {
              for (String contextRoot : activeContextRoots) {
                  virtualHost.addContextRoot(contextRoot, this);
              }
          }
          if (TraceComponent.isAnyTracingEnabled() && tc.isEventEnabled()) {
              Tr.event(this, tc, "add virtual host " + virtualHost);
          }
      }
docs: Required static reference