Slow leftShift GDK methods

    public static StringBuffer leftShift(String self, Object value) {
    	final CharSequence chseq;
    	if (value instanceof CharSequence)
    		chseq = (CharSequence)value;
    	else
    		chseq = String.valueOf(value);
    	final int capacity = 2 * (self.length() + chseq.length());
        return new StringBuffer(capacity).append(self).append(chseq);
    }

    public static StringBuffer leftShift(StringBuffer self, Object value) {
    	if (value instanceof CharSequence)
    		return self.append((CharSequence)value);
    	else
    		return self.append(value);
    }

    public static StringBuilder leftShift(StringBuilder self, Object value) {
    	if (value instanceof CharSequence)
    		return self.append((CharSequence)value);
    	else
    		return self.append(value);
    }