code: ///////////////////////////////////////////////////////////////////////////////
  // For information as to what this class does, see the Javadoc, below.       //
  // Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,       //
  // 2007, 2008, 2009, 2010, 2014, 2015 by Peter Spirtes, Richard Scheines, Joseph   //
  // Ramsey, and Clark Glymour.                                                //
  //                                                                           //
  // This program is free software; you can redistribute it and/or modify      //
  // it under the terms of the GNU General Public License as published by      //
  // the Free Software Foundation; either version 2 of the License, or         //
  // (at your option) any later version.                                       //
  //                                                                           //
  // This program is distributed in the hope that it will be useful,           //
  // but WITHOUT ANY WARRANTY; without even the implied warranty of            //
  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the             //
  // GNU General Public License for more details.                              //
  //                                                                           //
  // You should have received a copy of the GNU General Public License         //
  // along with this program; if not, write to the Free Software               //
  // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA //
  ///////////////////////////////////////////////////////////////////////////////
  
  package edu.cmu.tetrad.util;
  
  
  import java.util.*;
  
  /**
   * Logger configuration.
   *
   * @author Tyler Gibson
   */
  public class DefaultTetradLoggerConfig implements TetradLoggerConfig {
  
      static final long serialVersionUID = 23L;
  
      /**
       * The events that are supported.
       */
      private List<Event> events;
  
  
      /**
       * The event ids that are currently active.
       */
      private Set<String> active = new HashSet<>();
  
  
      /**
       * Constructs the config given the events in it.
       *
       * @param events The events that the logger reports.
       */
      public DefaultTetradLoggerConfig(List<Event> events) {
          if (events == null) {
              throw new NullPointerException("The given list of events must not be null");
          }
          this.events = new ArrayList<>(events);
      }
  
  
      /**
       * Constructs the config for the given event ids. This will create <code>Event</code>s with
       * no descriptions.
       *
       * @param events The events that the logger reports.
       */
      public DefaultTetradLoggerConfig(String... events) {
          this.events = new ArrayList<>(events.length);
          this.active = new HashSet<>();
          for (String event : events) {
              this.events.add(new DefaultEvent(event, "No Description"));
              this.active.add(event);
          }
      }
  
      public TetradLoggerConfig copy() {
          DefaultTetradLoggerConfig copy = new DefaultTetradLoggerConfig();
          copy.events = new ArrayList<>(this.events);
          copy.active = new HashSet<>(this.active);
          return copy;
      }
  
      /**
       * Generates a simple exemplar of this class to test serialization.
       */
      public static DefaultTetradLoggerConfig serializableInstance() {
          return new DefaultTetradLoggerConfig();
      }
  
      //=========================== public methods ================================//
  
      public boolean isEventActive(String id) {
          return this.active.contains(id);
      }
  
      public boolean isActive() {
          return !this.active.isEmpty();
      }
  
      public List<Event> getSupportedEvents() {
          return Collections.unmodifiableList(this.events);
      }
  
      public void setEventActive(String id, boolean active) {
          if (!contains(id)) {
              throw new IllegalArgumentException("There is no event known under the given id: " + id);
          }
          if (active) {
              this.active.add(id);
          } else {
              this.active.remove(id);
          }
      }
  
      public String toString() {
          StringBuilder buf = new StringBuilder();
          buf.append("\nDefaultTetradLoggerConfig: events as follows:");
  
          for (Event event : events) {
              buf.append("\n").append(event).append(active.contains(event.getId()) ? " (active)" : "");
          }
  
          return buf.toString();
      }
  
      //======================= Private Methods ==================================//
  
      private boolean contains(String id) {
          for (Event event : this.events) {
              if (id.equals(event.getId())) {
                  return true;
              }
          }
          return false;
      }
  
      //================================= Inner class ==================================//
  
      public static class DefaultEvent implements TetradLoggerConfig.Event {
          static final long serialVersionUID = 23L;
  
          private String id;
          private String description;
  
  
          public DefaultEvent(String id, String description) {
              if (id == null) {
                  throw new NullPointerException("The given id must not be null");
              }
              if (description == null) {
                  throw new NullPointerException("The given description must not be null");
              }
              this.id = id;
              this.description = description;
          }
  
  
          /**
           * Generates a simple exemplar of this class to test serialization.
           */
          public static DefaultEvent serializableInstance() {
              return new DefaultEvent("", "");
          }
  
          public String getId() {
              return this.id;
          }
  
          public String getDescription() {
              return this.description;
          }
  
          public String toString() {
              return "Event(" + id + ", " + description + ")";
          }
      }
  
  }
  
  
  
  
  