code: List<VariantAnnotationMessage> splitMessages(final String s,
                                                   final ConversionStringency stringency,
                                                   final Logger logger) throws ConversionException {
          return Splitter
              .on("&")
              .omitEmptyStrings()
              .splitToList(s)
              .stream()
              .map(m -> variantAnnotationMessageConverter.convert(m, stringency, logger))
              .collect(toList());
      }
docs: Split the specified string into a list of variant annotation messages.
  
  @param s string to split
  @param stringency conversion stringency, must not be null
  @param logger logger, must not be null
  @return the specified string split into a list of variant annotation messages
  @throws ConversionException if conversion fails and the specified conversion stringency is strict
  @throws NullPointerException if either conversion stringency or logger are null