docs: protected Person getPersonById(String id) {
  		Person person = null;
  		try {
  			Long personId = Long.valueOf(id);
  			if (logger.isDebugEnabled()) {
  				logger.debug("Retrieving Person with id=[{}]", personId);
  			}
  			person = entityManager.find(Person.class, personId);
  		} catch (NumberFormatException e) {
  			if (logger.isWarnEnabled()) {
  				logger.warn("Invalid number format: {}", id);
  			}
  		}
  		if (person == null) {
  			throw new IllegalArgumentException();
  		}
  		return person;
  	}