code: public void importFrom(Reader r) {
          BufferedReader reader = new BufferedReader(r);
          String s;
          
          Iterator<String> iter = 
              new RegexLineIterator(
                      new LineReadingIterator(reader),
                      RegexLineIterator.COMMENT_LINE,
                      RegexLineIterator.NONWHITESPACE_ENTRY_TRAILING_COMMENT,
                      RegexLineIterator.ENTRY);
  
          while (iter.hasNext()) {
              s = (String) iter.next();
              add(s.toLowerCase());
          }
      }
docs: Read a set of SURT prefixes from a reader source; keep sorted and
  with redundant entries removed.
  
  @param r reader over file of SURT_format strings
  @throws IOException