code: ///////////////////////////////////////////////////////////////////////////
  //                   __                _      _   ________               //
  //                  / /   ____  ____ _(_)____/ | / / ____/               //
  //                 / /   / __ \/ __ `/ / ___/  |/ / / __                 //
  //                / /___/ /_/ / /_/ / / /__/ /|  / /_/ /                 //
  //               /_____/\____/\__, /_/\___/_/ |_/\____/                  //
  //                           /____/                                      //
  //                                                                       //
  //               The Next Generation Logic Library                       //
  //                                                                       //
  ///////////////////////////////////////////////////////////////////////////
  //                                                                       //
  //  Copyright 2015-20xx Christoph Zengler                                //
  //                                                                       //
  //  Licensed 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.                       //
  //                                                                       //
  ///////////////////////////////////////////////////////////////////////////
  
  /*
   * MiniSat -- Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
   * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
   * associated documentation files (the "Software"), to deal in the Software without restriction,
   * including without limitation the rights to use, copy, modify, merge, publish, distribute,
   * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   * The above copyright notice and this permission notice shall be included in all copies or
   * substantial portions of the Software.
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
   * NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
   * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
   * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
   * OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   */
  
  package org.logicng.solvers.datastructures;
  
  /**
   * A watcher for clauses for MiniSAT-style solvers.
   * @version 1.0.1
   * @since 1.0
   */
  public final class MSWatcher {
      private final MSClause clause;
      private final int blocker;
  
      /**
       * Constructs a new watcher.
       * @param clause  the watched clause
       * @param blocker the blocking literal
       */
      public MSWatcher(final MSClause clause, final int blocker) {
          this.clause = clause;
          this.blocker = blocker;
      }
  
      /**
       * Returns the blocking literal of this watcher.
       * @return the blocking literal of this watcher
       */
      public int blocker() {
          return this.blocker;
      }
  
      /**
       * Returns the watched clause of this watcher.
       * @return the watched clause of this watcher
       */
      public MSClause clause() {
          return this.clause;
      }
  
      @Override
      public int hashCode() {
          return this.clause.hashCode();
      }
  
      @Override
      public boolean equals(final Object other) {
          return this == other || other instanceof MSWatcher && this.clause == (((MSWatcher) other).clause);
      }
  
      @Override
      public String toString() {
          return String.format("MSWatcher{clause=%s, blocker=%d}", this.clause, this.blocker);
      }
  }
  