docs: public void setFromString(String sectionNumber, int level) {
  		assert level >= 1;
  		final String[] numbers = sectionNumber.split("[^0-9]+"); //$NON-NLS-1$
  		final int len = Math.max(0, this.numbers.size() - numbers.length);
  		for (int i = 0; i < len; ++i) {
  			this.numbers.removeLast();
  		}
  		for (int i = 0; i < numbers.length && i < level; ++i) {
  			this.numbers.addLast(Integer.valueOf(numbers[i]));
  		}
  	}