code: private Content getNonBreakContent(String key) {
          String text = resources.getText(key); // TODO: cache
          Content c = new ContentBuilder();
          int start = 0;
          int p;
          while ((p = text.indexOf(" ", start)) != -1) {
              c.addContent(text.substring(start, p));
              c.addContent(RawHtml.nbsp);
              start = p + 1;
          }
          c.addContent(text.substring(start));
          return c; // TODO: should be made immutable
      }
docs: Gets a {@code Content} object, containing the string for
  a given key in the doclet's resources, substituting
  <code>&nbsp;</code> for any space characters found in
  the named resource string.
  
  @param key the key for the desired string
  @return a content tree for the string