code: public Float calculateExtinctionCoefficient(String notation)
  			throws ExtinctionCoefficientException, ValidationException, MonomerLoadingException, ChemistryException {
  		Float result = ExtinctionCoefficient.getInstance().calculate(validate(notation));
  		setMonomerFactoryToDefault(notation);
  		return result;
  	}
docs: method to calculate from a non-ambiguous HELM string the extinction
  coefficient
  
  @param notation
  HELM input
  @return extinction coefficient from the HELM input
  @throws ExtinctionCoefficientException
  if the extinction coefficient can not be calculated
  @throws ValidationException
  if the HELM input is not valid
  @throws MonomerLoadingException
  if the MonomerFactory can not be refreshed
  @throws ChemistryException
  if the Chemistry Engine can not be initialized