code: public String readRNA(String rna) throws org.helm.notation2.parser.exceptionparser.NotationException,
  			FastaFormatException, ChemistryException, org.helm.notation2.exception.NucleotideLoadingException {
  		return SequenceConverter.readRNA(rna).toHELM2();
  	}
docs: method to read a single rna sequence and generates HELM
  
  @param rna
  rna sequence
  @return HELM
  @throws org.helm.notation2.parser.exceptionparser.NotationException
  if the notation object can not be built
  @throws FastaFormatException
  if the rna-sequence is not in the right format HELM
  @throws ChemistryException
  if chemistry engine can not be initialized
  @throws org.helm.notation2.exception.NucleotideLoadingException
  if nucleotides can not be loaded