docs: public List<Attribute> asList() {
          ArrayList<Attribute> list = new ArrayList<>(size);
          for (int i = 0; i < size; i++) {
              Attribute attr = vals[i] == null ?
                  new BooleanAttribute(keys[i]) : // deprecated class, but maybe someone still wants it
                  new Attribute(keys[i], vals[i], Attributes.this);
              list.add(attr);
          }
          return Collections.unmodifiableList(list);
      }