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.remote;
  
  import java.io.Serializable;
  import java.util.Map;
  import java.util.UUID;
  import org.openqa.selenium.internal.Require;
  import org.openqa.selenium.json.JsonException;
  
  public class SessionId implements Serializable {
  
    private final String opaqueKey;
  
    public SessionId(UUID uuid) {
      this(Require.nonNull("Session ID key", uuid).toString());
    }
  
    public SessionId(String opaqueKey) {
      this.opaqueKey = Require.nonNull("Session ID key", opaqueKey);
    }
  
    @Override
    public String toString() {
      return opaqueKey;
    }
  
    @Override
    public int hashCode() {
      return opaqueKey.hashCode();
    }
  
    @Override
    public boolean equals(Object obj) {
      return obj instanceof SessionId && opaqueKey.equals(((SessionId) obj).opaqueKey);
    }
  
    private String toJson() {
      return opaqueKey;
    }
  
    private static SessionId fromJson(Object raw) {
      if (raw instanceof String) {
        return new SessionId(String.valueOf(raw));
      }
  
      if (raw instanceof Map) {
        Map<?, ?> map = (Map<?, ?>) raw;
        if (map.get("value") instanceof String) {
          return new SessionId(String.valueOf(map.get("value")));
        }
      }
  
      throw new JsonException("Unable to coerce session id from " + raw);
    }
  }
  