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.logging;
  
  import java.util.Collections;
  import java.util.Set;
  
  /** Stores and retrieves logs in-process (i.e. without any RPCs). */
  public abstract class LocalLogs implements Logs {
  
    private static final LocalLogs NULL_LOGGER =
        new LocalLogs() {
          @Override
          public LogEntries get(String logType) {
            return new LogEntries(Collections.emptyList());
          }
  
          @Override
          public Set<String> getAvailableLogTypes() {
            return Collections.emptySet();
          }
  
          @Override
          public void addEntry(String logType, LogEntry entry) {}
        };
  
    /**
     * Logger which doesn't do anything.
     *
     * @return the null logger
     */
    public static LocalLogs getNullLogger() {
      return NULL_LOGGER;
    }
  
    public static LocalLogs getStoringLoggerInstance(Set<String> logTypesToIgnore) {
      return new StoringLocalLogs(logTypesToIgnore);
    }
  
    public static LocalLogs getHandlerBasedLoggerInstance(
        LoggingHandler loggingHandler, Set<String> logTypesToInclude) {
      return new HandlerBasedLocalLogs(loggingHandler, logTypesToInclude);
    }
  
    /**
     * See documentation of CompositeLocalLogs about the difference between the first LocalLogs
     * instance and the second one.
     *
     * @param predefinedTypeLogger LocalLogs which pre-defines the log types it stores.
     * @param allTypesLogger LocalLogs which can store log entries for all log types.
     * @return A LocalLogs instance.
     */
    public static LocalLogs getCombinedLogsHolder(
        LocalLogs predefinedTypeLogger, LocalLogs allTypesLogger) {
      return new CompositeLocalLogs(predefinedTypeLogger, allTypesLogger);
    }
  
    protected LocalLogs() {}
  
    @Override
    public abstract LogEntries get(String logType);
  
    public abstract void addEntry(String logType, LogEntry entry);
  }
  