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 static org.openqa.selenium.json.Json.MAP_TYPE;
  import static org.openqa.selenium.json.JsonType.END;
  import static org.openqa.selenium.remote.http.Contents.reader;
  import static org.openqa.selenium.remote.http.Contents.string;
  
  import java.io.IOException;
  import java.io.Reader;
  import java.io.UncheckedIOException;
  import java.lang.reflect.Type;
  import org.openqa.selenium.json.Json;
  import org.openqa.selenium.json.JsonInput;
  import org.openqa.selenium.remote.ErrorCodec;
  import org.openqa.selenium.remote.http.HttpResponse;
  
  public class Values {
  
    private static final Json JSON = new Json();
    private static final ErrorCodec ERRORS = ErrorCodec.createDefault();
  
    public static <T> T get(HttpResponse response, Type typeOfT) {
      try (Reader reader = reader(response);
          JsonInput input = JSON.newInput(reader)) {
  
        // Alright then. We might be dealing with the object we expected, or we might have an
        // error. We shall assume that a non-200 http status code indicates that something is
        // wrong.
        if (response.getStatus() != 200) {
          throw ERRORS.decode(JSON.toType(string(response), MAP_TYPE));
        }
  
        if (Void.class.equals(typeOfT) && input.peek() == END) {
          return null;
        }
  
        input.beginObject();
  
        while (input.hasNext()) {
          if ("value".equals(input.nextName())) {
            return input.read(typeOfT);
          } else {
            input.skipValue();
          }
        }
  
        throw new IllegalStateException("Unable to locate value: " + string(response));
      } catch (IOException e) {
        throw new UncheckedIOException(e);
      }
    }
  }
  