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.web;
  
  import java.util.HashMap;
  import java.util.Map;
  import java.util.function.Predicate;
  import org.openqa.selenium.internal.Require;
  import org.openqa.selenium.json.Json;
  import org.openqa.selenium.remote.http.HttpHandler;
  import org.openqa.selenium.remote.http.HttpRequest;
  import org.openqa.selenium.remote.http.HttpResponse;
  import org.openqa.selenium.remote.http.Routable;
  
  public class CombinedHandler implements Predicate<HttpRequest>, Routable, HttpHandler {
  
    private final Map<Routable, HttpHandler> handlers = new HashMap<>();
  
    public void addHandler(Routable handler) {
      handlers.put(Require.nonNull("Handler", handler), handler);
    }
  
    @Override
    public boolean test(HttpRequest request) {
      return matches(request);
    }
  
    @Override
    public boolean matches(HttpRequest req) {
      return handlers.keySet().stream()
          .map(p -> p.matches(req))
          .reduce(Boolean::logicalOr)
          .orElse(false);
    }
  
    @Override
    public HttpResponse execute(HttpRequest req) {
      return handlers.entrySet().stream()
          .filter(entry -> entry.getKey().matches(req))
          .findFirst()
          .map(Map.Entry::getValue)
          .orElse(new NoHandler(new Json()))
          .execute(req);
    }
  }
  