code: @Override
  	public Object getValueAt(final int rowIndex, final int columnIndex)
  	{
  		final String key = (String)data.get(rowIndex);
  		final PropertiesColumns column = PropertiesColumns.values()[columnIndex];
  		switch (column)
  		{
  			case KEY :
  				return key;
  			case VALUE :
  				return data.get(key);
  		}
  		return null;
  	}
docs: {@inheritDoc}