code: private static String formatProperties(ArgumentUnit argumentUnit)
      {
  		final StringBuilder sb = new StringBuilder("Properties:" + System.lineSeparator());
  
  		final Properties properties = ArgumentUnitUtils.getProperties(argumentUnit);
  		for (final Map.Entry<Object, Object> entry : properties.entrySet()) {
  			if (entry.getValue() != null) {
  				sb.append("   ");
  				sb.append(entry.getKey());
  				sb.append(": ");
  				sb.append(entry.getValue());
  				sb.append(System.lineSeparator());
  			}
  		}
  
  		return sb.toString();
      }
docs: Prints to string all non-null {@code properties} of the the given unit
  
  @param argumentUnit argument unit
  @return string