docs: private void processRunAs(Servlet servlet) {
          String servletName = servlet.getServletName();
          Map<String, ConfigItem<String>> runAsMap = this.configurator.getConfigItemMap(RUN_AS_KEY);
          ConfigItem<String> existingRunAs = runAsMap.get(servletName);
  
          RunAs runAs = servlet.getRunAs();
          String roleName = (runAs != null) ? runAs.getRoleName() : null;
          if (runAs != null) {
              if (existingRunAs == null) {
                  runAsMap.put(servletName, this.configurator.createConfigItem(roleName));
                  if (roleName != null)
                      this.servletNameToRunAsRole.put(servletName, roleName);
              } else {
                  this.configurator.validateDuplicateKeyValueConfiguration(SERVLET_KEY, SERVLET_NAME_KEY, servletName, RUN_AS_KEY, roleName, existingRunAs);
              }
          }
          if ((TraceComponent.isAnyTracingEnabled()) && (SecurityServletConfiguratorHelper.tc.isDebugEnabled()))
              Tr.debug(SecurityServletConfiguratorHelper.tc, "servletNameToRunAsRole: " + this.servletNameToRunAsRole, new Object[0]);
      }