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.netty.server;
  
  import io.netty.channel.ChannelHandlerContext;
  import io.netty.channel.SimpleChannelInboundHandler;
  import java.util.concurrent.ExecutorService;
  import java.util.concurrent.Executors;
  import org.openqa.selenium.internal.Require;
  import org.openqa.selenium.remote.ErrorFilter;
  import org.openqa.selenium.remote.http.HttpHandler;
  import org.openqa.selenium.remote.http.HttpRequest;
  import org.openqa.selenium.remote.http.HttpResponse;
  
  class SeleniumHandler extends SimpleChannelInboundHandler<HttpRequest> {
  
    private static final ExecutorService EXECUTOR = Executors.newCachedThreadPool();
    private final HttpHandler seleniumHandler;
  
    public SeleniumHandler(HttpHandler seleniumHandler) {
      super(HttpRequest.class);
      this.seleniumHandler = Require.nonNull("HTTP handler", seleniumHandler).with(new ErrorFilter());
    }
  
    @Override
    protected void channelRead0(ChannelHandlerContext ctx, HttpRequest msg) {
      EXECUTOR.submit(
          () -> {
            HttpResponse res = seleniumHandler.execute(msg);
            ctx.writeAndFlush(res);
          });
    }
  }
  