private static String changePrefix(String string, int displayedWidth) {
private static String changePrefix(String string, int displayedWidth, boolean useSpaces, int tabWidth) {
	private static String changePrefix(String string, int displayedWidth) {		// assumption: string contains no whitspaces		final StringBuffer buffer= new StringBuffer(string);		int column= calculateDisplayedWidth(buffer.toString());		if (column > displayedWidth)			return string;				if (useSpaces()) {			while (column != displayedWidth) {				buffer.append(' ');				++column;			}					} else {			final int tabWidth= JavaPlugin.getDefault().getPreferenceStore().getInt(PreferenceConstants.EDITOR_TAB_WIDTH);			while (column != displayedWidth) {				if (column + tabWidth - (column % tabWidth) <= displayedWidth) {					buffer.append('\t');					column += tabWidth - (column % tabWidth);				} else {					buffer.append(' ');					++column;				}			}					}		return buffer.toString();	}