public static final void setIndentString(String indent) {
		if (indent.equals(" ") || indent.equals("  ") || indent.equals("    ") || indent.equals("      ")
				|| indent.equals("        ") || indent.equals("\t")) {
			indentString = indent;
		} else
			throw new Error("setIndentString: invalid indent string, expected 1, 2, 4, 6, 8 spaces or tab");
	}