public static String pformat(Collection<?> c){
		if(c.size() == 0) return "[]";
		
		StringBuilder  result = new StringBuilder("[");
		for(Object elem : c){
			if(c.size() != 1)
				result.append("\n ");
			result.append(elem);
		}
		if(c.size() != 1)
			result.append("\n");
		result.append("]");
		return result.toString();
	}