code: protected String validateMetaLine(String metaLineStr)
      throws IOException {
          if (metaLineStr.length() > MAX_METADATA_LINE_LENGTH) {
              throw new IOException("Metadata line too long ("
                  + metaLineStr.length() + ">" + MAX_METADATA_LINE_LENGTH 
                  + "): " + metaLineStr);
          }
       	Matcher m = METADATA_LINE_PATTERN.matcher(metaLineStr);
          if (!m.matches()) {
              throw new IOException("Metadata line doesn't match expected" +
                  " pattern: " + metaLineStr);
          }
          return metaLineStr;
      }
docs: Test that the metadata line is valid before writing.
  @param metaLineStr
  @throws IOException
  @return The passed in metaline.