str.getChars(0, strLen, buffer, size);
str.getChars(0, width, buffer, size);
    public StrBuilder appendFixedWidthPadRight(Object obj, int width, char padChar) {        if (width > 0) {            ensureCapacity(size + width);            String str = (obj == null ? getNullText() : obj.toString());            int strLen = str.length();            if (strLen >= width) {                str.getChars(0, strLen, buffer, size);            } else {                int padLen = width - strLen;                str.getChars(0, strLen, buffer, size);                for (int i = 0; i < padLen; i++) {                    buffer[size + strLen + i] = padChar;                }            }            size += width;        }        return this;    }