code: public static <T> T readLines(URL url, Charset charset,
        LineProcessor<T> callback) throws IOException {
      return asCharSource(url, charset).readLines(callback);
    }
docs: Streams lines from a URL, stopping when our callback returns false, or we
  have read all of the lines.
  
  @param url the URL to read from
  @param charset the charset used to decode the input stream; see {@link
  Charsets} for helpful predefined constants
  @param callback the LineProcessor to use to handle the lines
  @return the output of processing the lines
  @throws IOException if an I/O error occurs