code: // Licensed to the Software Freedom Conservancy (SFC) under one
  // or more contributor license agreements.  See the NOTICE file
  // distributed with this work for additional information
  // regarding copyright ownership.  The SFC licenses this file
  // to you under the Apache License, Version 2.0 (the
  // "License"); you may not use this file except in compliance
  // with the License.  You may obtain a copy of the License at
  //
  //   http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing,
  // software distributed under the License is distributed on an
  // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  // KIND, either express or implied.  See the License for the
  // specific language governing permissions and limitations
  // under the License.
  
  package org.openqa.selenium.grid.server;
  
  import static org.openqa.selenium.grid.config.StandardGridRoles.EVENT_BUS_ROLE;
  import static org.openqa.selenium.grid.server.EventBusOptions.EVENTS_SECTION;
  
  import com.beust.jcommander.Parameter;
  import com.google.auto.service.AutoService;
  import com.google.common.collect.ImmutableSet;
  import java.util.Set;
  import org.openqa.selenium.grid.config.ConfigValue;
  import org.openqa.selenium.grid.config.HasRoles;
  import org.openqa.selenium.grid.config.Role;
  
  @AutoService(HasRoles.class)
  public class EventBusFlags implements HasRoles {
  
    @Parameter(
        names = {"--publish-events"},
        description = "Connection string for publishing events to the event bus")
    @ConfigValue(section = EVENTS_SECTION, name = "publish", example = "\"tcp://*:1233\"")
    private String publishString;
  
    @Parameter(
        names = {"--subscribe-events"},
        description = "Connection string for subscribing to events from the event bus")
    @ConfigValue(section = EVENTS_SECTION, name = "subscribe", example = "\"tcp://*1232\"")
    private String subscribeString;
  
    @Parameter(
        names = {"--bind-bus"},
        description =
            "Whether the connection string should be bound or connected. When true, the "
                + "component will be bound to the Event Bus (as in the Event Bus will also be "
                + "started by the component, typically by the Distributor and the Hub). When "
                + "false, the component will connect to the Event Bus.",
        arity = 1)
    @ConfigValue(section = EVENTS_SECTION, name = "bind", example = "false")
    // We use the Boolean here so we can differentiate between there being no option, and a default
    // false value.
    private Boolean bind;
  
    @Parameter(
        names = {"--events-implementation"},
        description = "Full classname of non-default event bus implementation")
    @ConfigValue(
        section = EVENTS_SECTION,
        name = "implementation",
        example = "\"org.openqa.selenium.events.zeromq.ZeroMqEventBus\"")
    private String implementation;
  
    @Override
    public Set<Role> getRoles() {
      return ImmutableSet.of(EVENT_BUS_ROLE);
    }
  }
  