code: public List<String> values(String name) {
          List<String> result = null;
          for (int i = 0, size = size(); i < size; i++) {
              if (name.equalsIgnoreCase(name(i))) {
                  if (result == null) result = new ArrayList<>(2);
                  result.add(value(i));
              }
          }
          return result != null
                  ? Collections.unmodifiableList(result)
                  : Collections.<String>emptyList();
      }
docs: Returns an immutable list of the header values for {@code name}.