code: /*
   * Copyright (c) 2003, 2016, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
   * particular file as subject to the "Classpath" exception as provided
   * by Oracle in the LICENSE file that accompanied this code.
   *
   * This code 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
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   */
  
  /*
   * DIFFBLUE MODEL LIBRARY
   * At the moment, the methods defined in this class are not called anywhere
   * because the classes that extend this class override each method without
   * calling methods from this class.
   *
   * This file is only present to maintain the original inheritance. However, it
   * would make sense to implement some of the modelled methods here instead of
   * in the StringBuilder and StringBuffer classes, in the case these methods
   * are modelled in a similar way.
   */
  
  package java.lang;
  
  import org.cprover.CProver;
  
  abstract class AbstractStringBuilder implements Appendable, CharSequence {
  
      AbstractStringBuilder() {}
  
      AbstractStringBuilder(int capacity) {}
  
      @Override
      public int length() {
          return CProver.nondetInt();
      }
  
      public int capacity() {
          CProver.notModelled();
          return CProver.nondetInt();
      }
  
      public void ensureCapacity(int minimumCapacity) {}
  
      public void trimToSize() {}
  
      public void setLength(int newLength) {}
  
      @Override
      public char charAt(int index) {
          return 'c';
      }
  
      public int codePointAt(int index) {
          return CProver.nondetInt();
      }
  
      public int codePointBefore(int index) {
          return CProver.nondetInt();
      }
  
      public int codePointCount(int beginIndex, int endIndex) {
          return CProver.nondetInt();
      }
  
      public int offsetByCodePoints(int index, int codePointOffset) {
          return CProver.nondetInt();
      }
  
      public void getChars(int srcBegin, int srcEnd, char[] dst, int dstBegin) {
        CProver.notModelled();
      }
  
      public void setCharAt(int index, char ch) {}
  
      public AbstractStringBuilder append(Object obj) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public AbstractStringBuilder append(String str) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public AbstractStringBuilder append(StringBuffer sb) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      AbstractStringBuilder append(AbstractStringBuilder asb) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      @Override
      public AbstractStringBuilder append(CharSequence s) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      @Override
      public AbstractStringBuilder append(CharSequence s, int start, int end) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public AbstractStringBuilder append(char[] str) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public AbstractStringBuilder append(char str[], int offset, int len) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public AbstractStringBuilder append(boolean b) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      @Override
      public AbstractStringBuilder append(char c) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public AbstractStringBuilder append(int i) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public AbstractStringBuilder append(long l) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public AbstractStringBuilder append(float f) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public AbstractStringBuilder append(double d) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public AbstractStringBuilder delete(int start, int end) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public AbstractStringBuilder appendCodePoint(int codePoint) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public AbstractStringBuilder deleteCharAt(int index) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public AbstractStringBuilder replace(int start, int end, String str) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public String substring(int start) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      @Override
      public CharSequence subSequence(int start, int end) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public String substring(int start, int end) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public AbstractStringBuilder insert(int index, char[] str, int offset,
                                                 int len) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public AbstractStringBuilder insert(int offset, Object obj) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public AbstractStringBuilder insert(int offset, String str) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public AbstractStringBuilder insert(int offset, char[] str) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public AbstractStringBuilder insert(int dstOffset, CharSequence s) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public AbstractStringBuilder insert(int dstOffset, CharSequence s,
                                                 int start, int end) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public AbstractStringBuilder insert(int offset, boolean b) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public AbstractStringBuilder insert(int offset, char c) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public AbstractStringBuilder insert(int offset, int i) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public AbstractStringBuilder insert(int offset, long l) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public AbstractStringBuilder insert(int offset, float f) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public AbstractStringBuilder insert(int offset, double d) {
          return CProver.nondetWithNullForNotModelled();
      }
  
      public int indexOf(String str) {
          return CProver.nondetInt();
      }
  
      public int indexOf(String str, int fromIndex) {
          return CProver.nondetInt();
      }
  
      public int lastIndexOf(String str) {
          return CProver.nondetInt();
      }
  
      public int lastIndexOf(String str, int fromIndex) {
          return CProver.nondetInt();
      }
  
      public AbstractStringBuilder reverse() {
          return CProver.nondetWithNullForNotModelled();
      }
  
      @Override
      public abstract String toString();
  
      // Method should not be used in the models
      // final char[] getValue();
  }
  