code: private InternetHeaders parseHeaders(DataSource ds) {
          try {
              return new InternetHeaders(ds.getInputStream());
          } catch (MessagingException e) {
              throw new RuntimeException(e);
          } catch (IOException e) {
              throw new RuntimeException(e);
          }
      }
docs: Parses the headers.
  
  @param ds
  the ds
  @return the internet headers