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.node;
  
  import static org.openqa.selenium.remote.http.Contents.asJson;
  import static org.openqa.selenium.remote.http.Contents.string;
  
  import com.google.common.collect.ImmutableMap;
  import java.io.UncheckedIOException;
  import java.util.HashMap;
  import org.openqa.selenium.WebDriverException;
  import org.openqa.selenium.grid.data.CreateSessionRequest;
  import org.openqa.selenium.grid.data.CreateSessionResponse;
  import org.openqa.selenium.internal.Either;
  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;
  
  class NewNodeSession implements HttpHandler {
  
    private final Node node;
    private final Json json;
  
    NewNodeSession(Node node, Json json) {
      this.node = Require.nonNull("Node", node);
      this.json = Require.nonNull("Json converter", json);
    }
  
    @Override
    public HttpResponse execute(HttpRequest req) throws UncheckedIOException {
      CreateSessionRequest incoming = json.toType(string(req), CreateSessionRequest.class);
  
      Either<WebDriverException, CreateSessionResponse> result = node.newSession(incoming);
  
      HashMap<String, Object> value = new HashMap<>();
  
      HashMap<String, Object> response = new HashMap<>();
      if (result.isRight()) {
        response.put("sessionResponse", result.right());
      } else {
        WebDriverException exception = result.left();
        response.put(
            "exception",
            ImmutableMap.of(
                "error", exception.getClass(),
                "message", exception.getMessage()));
      }
  
      value.put("value", response);
  
      return new HttpResponse().setContent(asJson(value));
    }
  }
  