code: public void addHeader(String name, String value) {
          headers.add(name, value);
          List<String> list = caseSensitiveHeaders.get(name);
          if (list == null) {
              list = new ArrayList<String>();
              caseSensitiveHeaders.put(name, list);
          }
          list.add(value);
      }
docs: Adds and normalizes the header.
  @param name
  @param value