* @return this <code>StringBuffer</code>   * @see #append(Object)   * @since 1.5   */  public synchronized StringBuffer append(CharSequence sequence)  {    if (sequence == null)      sequence = "null";    return append(sequence, 0, sequence.length());  }  /**   * Append the specified subsequence of the <code>CharSequence</code>   * argument to this <code>StringBuffer</code>.   *   * @param sequence the <code>CharSequence</code> to append   * @param start the starting index   * @param end one past the ending index   * @return this <code>StringBuffer</code>   * @see #append(Object)   * @since 1.5   */  public synchronized StringBuffer append(CharSequence sequence,					  int start, int end)  {    if (sequence == null)      sequence = "null";    if (start < 0 || end < 0 || start > end || end > sequence.length())      throw new IndexOutOfBoundsException();    ensureCapacity_unsynchronized(this.count + end - start);    for (int i = start; i < end; ++i)      value[count++] = sequence.charAt(i);    return this;  }  /**   * Append the <code>char</code> array to this <code>StringBuffer</code>.   * This is similar (but more efficient) than   * <code>append(new String(data))</code>, except in the case of null.   *   * @param data the <code>char[]</code> to append   * @return this <code>StringBuffer</code>   * @throws NullPointerException if <code>str</code> is <code>null</code>   * @see #append(char[], int, int)   */  public StringBuffer append(char[] data)  {    return append(data, 0, data.length);  }  /**   * Append part of the <code>char</code> array to this   * <code>StringBuffer</code>. This is similar (but more efficient) than   * <code>append(new String(data, offset, count))</code>, except in the case   * of null.   *   * @param data the <code>char[]</code> to append   * @param offset the start location in <code>str</code>   * @param count the number of characters to get from <code>str</code>   * @return this <code>StringBuffer</code>   * @throws NullPointerException if <code>str</code> is <code>null</code>   * @throws IndexOutOfBoundsException if offset or count is out of range   *         (while unspecified, this is a StringIndexOutOfBoundsException)   */  public synchronized StringBuffer append(char[] data, int offset, int count)  {    if (offset < 0 || count < 0 || offset > data.length - count)      throw new StringIndexOutOfBoundsException();    ensureCapacity_unsynchronized(this.count + count);    VMSystem.arraycopy(data, offset, value, this.count, count);    this.count += count;    return this;  }  /**   * Append the <code>String</code> value of the argument to this   * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert   * to <code>String</code>.   *   * @param bool the <code>boolean</code> to convert and append   * @return this <code>StringBuffer</code>   * @see String#valueOf(boolean)   */  public StringBuffer append(boolean bool)  {    return append(bool ? "true" : "false");  }  /**   * Append the <code>char</code> to this <code>StringBuffer</code>.   *   * @param ch the <code>char</code> to append   * @return this <code>StringBuffer</code>   */  public synchronized StringBuffer append(char ch)  {    ensureCapacity_unsynchronized(count + 1);    value[count++] = ch;    return this;  }  /**   * Append the code point to this <code>StringBuffer</code>.   * This is like #append(char), but will append two characters   * if a supplementary code point is given.   *   * @param code the code point to append   * @return this <code>StringBuffer</code>   * @see Character#toChars(int, char[], int)   * @since 1.5   */  public synchronized StringBuffer appendCodePoint(int code)  {    int len = Character.charCount(code);    ensureCapacity_unsynchronized(count + len);    Character.toChars(code, value, count);    count += len;    return this;  }  /**   * Append the <code>String</code> value of the argument to this   * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert   * to <code>String</code>.   *   * @param inum the <code>int</code> to convert and append   * @return this <code>StringBuffer</code>   * @see String#valueOf(int)   */  // This is native in libgcj, for efficiency.  public StringBuffer append(int inum)  {    return append(String.valueOf(inum));  }  /**   * Append the <code>String</code> value of the argument to this   * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert   * to <code>String</code>.   *   * @param lnum the <code>long</code> to convert and append   * @return this <code>StringBuffer</code>   * @see String#valueOf(long)   */  public StringBuffer append(long lnum)  {    return append(Long.toString(lnum, 10));  }  /**   * Append the <code>String</code> value of the argument to this   * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert   * to <code>String</code>.   *   * @param fnum the <code>float</code> to convert and append   * @return this <code>StringBuffer</code>   * @see String#valueOf(float)   */  public StringBuffer append(float fnum)  {    return append(Float.toString(fnum));  }  /**   * Append the <code>String</code> value of the argument to this   * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert   * to <code>String</code>.   *   * @param dnum the <code>double</code> to convert and append   * @return this <code>StringBuffer</code>   * @see String#valueOf(double)   */  public StringBuffer append(double dnum)  {    return append(Double.toString(dnum));  }  /**   * Delete characters from this <code>StringBuffer</code>.   * <code>delete(10, 12)</code> will delete 10 and 11, but not 12. It is   * harmless for end to be larger than length().   *   * @param start the first character to delete   * @param end the index after the last character to delete   * @return this <code>StringBuffer</code>   * @throws StringIndexOutOfBoundsException if start or end are out of bounds   * @since 1.2   */  public synchronized StringBuffer delete(int start, int end)  {    if (start < 0 || start > count || start > end)      throw new StringIndexOutOfBoundsException(start);    if (end > count)      end = count;    // This will unshare if required.    ensureCapacity_unsynchronized(count);    if (count - end != 0)      VMSystem.arraycopy(value, end, value, start, count - end);    count -= end - start;    return this;  }  /**   * Delete a character from this <code>StringBuffer</code>.   *   * @param index the index of the character to delete   * @return this <code>StringBuffer</code>   * @throws StringIndexOutOfBoundsException if index is out of bounds   * @since 1.2   */  public StringBuffer deleteCharAt(int index)  {    return delete(index, index + 1);  }  /**   * Replace characters between index <code>start</code> (inclusive) and   * <code>end</code> (exclusive) with <code>str</code>. If <code>end</code>   * is larger than the size of this StringBuffer, all characters after   * <code>start</code> are replaced.   *   * @param start the beginning index of characters to delete (inclusive)   * @param end the ending index of characters to delete (exclusive)   * @param str the new <code>String</code> to insert   * @return this <code>StringBuffer</code>   * @throws StringIndexOutOfBoundsException if start or end are out of bounds   * @throws NullPointerException if str is null   * @since 1.2   */  public synchronized StringBuffer replace(int start, int end, String str)  {    if (start < 0 || start > count || start > end)      throw new StringIndexOutOfBoundsException(start);    int len = str.count;    // Calculate the difference in 'count' after the replace.    int delta = len - (end > count ? count : end) + start;    ensureCapacity_unsynchronized(count + delta);    if (delta != 0 && end < count)      VMSystem.arraycopy(value, end, value, end + delta, count - end);    str.getChars(0, len, value, start);    count += delta;    return this;  }  /**   * Creates a substring of this StringBuffer, starting at a specified index   * and ending at the end of this StringBuffer.   *   * @param beginIndex index to start substring (base 0)   * @return new String which is a substring of this StringBuffer   * @throws StringIndexOutOfBoundsException if beginIndex is out of bounds   * @see #substring(int, int)   * @since 1.2   */  public String substring(int beginIndex)  {    return substring(beginIndex, count);  }  /**   * Creates a substring of this StringBuffer, starting at a specified index   * and ending at one character before a specified index. This is implemented   * the same as <code>substring(beginIndex, endIndex)</code>, to satisfy   * the CharSequence interface.   *   * @param beginIndex index to start at (inclusive, base 0)   * @param endIndex index to end at (exclusive)   * @return new String which is a substring of this StringBuffer   * @throws IndexOutOfBoundsException if beginIndex or endIndex is out of   *         bounds   * @see #substring(int, int)   * @since 1.4   */  public CharSequence subSequence(int beginIndex, int endIndex)  {    return substring(beginIndex, endIndex);  }  /**   * Creates a substring of this StringBuffer, starting at a specified index   * and ending at one character before a specified index.   *   * @param beginIndex index to start at (inclusive, base 0)   * @param endIndex index to end at (exclusive)   * @return new String which is a substring of this StringBuffer   * @throws StringIndexOutOfBoundsException if beginIndex or endIndex is out   *         of bounds   * @since 1.2   */  public synchronized String substring(int beginIndex, int endIndex)  {    int len = endIndex - beginIndex;    if (beginIndex < 0 || endIndex > count || endIndex < beginIndex)      throw new StringIndexOutOfBoundsException();    if (len == 0)      return "";    // Don't copy unless substring is smaller than 1/4 of the buffer.    boolean share_buffer = ((len << 2) >= value.length);    if (share_buffer)      this.shared = true;    // Package constructor avoids an array copy.    return new String(value, beginIndex, len, share_buffer);  }  /**   * Insert a subarray of the <code>char[]</code> argument into this   * <code>StringBuffer</code>.   *   * @param offset the place to insert in this buffer   * @param str the <code>char[]</code> to insert   * @param str_offset the index in <code>str</code> to start inserting from   * @param len the number of characters to insert   * @return this <code>StringBuffer</code>   * @throws NullPointerException if <code>str</code> is <code>null</code>   * @throws StringIndexOutOfBoundsException if any index is out of bounds   * @since 1.2   */  public synchronized StringBuffer insert(int offset,                                          char[] str, int str_offset, int len)  {    if (offset < 0 || offset > count || len < 0        || str_offset < 0 || str_offset > str.length - len)      throw new StringIndexOutOfBoundsException();    ensureCapacity_unsynchronized(count + len);    VMSystem.arraycopy(value, offset, value, offset + len, count - offset);    VMSystem.arraycopy(str, str_offset, value, offset, len);    count += len;    return this;  }  /**   * Insert the <code>String</code> value of the argument into this   * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert   * to <code>String</code>.   *   * @param offset the place to insert in this buffer   * @param obj the <code>Object</code> to convert and insert   * @return this <code>StringBuffer</code>   * @exception StringIndexOutOfBoundsException if offset is out of bounds   * @see String#valueOf(Object)   */  public StringBuffer insert(int offset, Object obj)  {    return insert(offset, obj == null ? "null" : obj.toString());  }  /**   * Insert the <code>String</code> argument into this   * <code>StringBuffer</code>. If str is null, the String "null" is used   * instead.   *   * @param offset the place to insert in this buffer   * @param str the <code>String</code> to insert   * @return this <code>StringBuffer</code>   * @throws StringIndexOutOfBoundsException if offset is out of bounds   */  public synchronized StringBuffer insert(int offset, String str)  {    if (offset < 0 || offset > count)      throw new StringIndexOutOfBoundsException(offset);    if (str == null)      str = "null";    int len = str.count;    ensureCapacity_unsynchronized(count + len);    VMSystem.arraycopy(value, offset, value, offset + len, count - offset);    str.getChars(0, len, value, offset);    count += len;    return this;  }  /**   * Insert the <code>CharSequence</code> argument into this   * <code>StringBuffer</code>.  If the sequence is null, the String   * "null" is used instead.   *   * @param offset the place to insert in this buffer   * @param sequence the <code>CharSequence</code> to insert   * @return this <code>StringBuffer</code>   * @throws IndexOutOfBoundsException if offset is out of bounds   * @since 1.5   */  public synchronized StringBuffer insert(int offset, CharSequence sequence)  {    if (sequence == null)      sequence = "null";    return insert(offset, sequence, 0, sequence.length());  }  /**   * Insert a subsequence of the <code>CharSequence</code> argument into this   * <code>StringBuffer</code>.  If the sequence is null, the String   * "null" is used instead.   *   * @param offset the place to insert in this buffer