code: private boolean headerSeparatorDemarcatesHeader(List<String> contents) {
          List<String> subContents = null;
          int index = contents.indexOf(configuration.getHeaderSeparator());
          if (index != -1) {
              // get every line above header separator
              subContents = contents.subList(0, index);
  
              for (String line : subContents) {
                  // header should only contain empty lines or lines with '=' in
                  if (!line.contains("=") && !line.isEmpty())  {
                      return false;
                  }
              }
              return true;
          } else {
              return false;
          }
      }
docs: Checks if header separator demarcates end of metadata header
  
  @param contents
  @return true if header separator resides at end of metadata header, false if not