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