code: public void populateContainer(Class<? extends FieldType> type, FieldContainer container, Integer id, byte[][] fixedData, Var2Data varData)
     {
        //System.out.println(container.getClass().getSimpleName()+": " + id);
        for (FieldItem item : m_map.values())
        {
           if (item.getType().getClass().equals(type))
           {
              //System.out.println(item.m_type);
              Object value = item.read(id, fixedData, varData);
              //System.out.println(item.m_type.getClass().getSimpleName() + "." + item.m_type +  ": " + value);
              container.set(item.getType(), value);
           }
        }
     }
docs: Given a container, and a set of raw data blocks, this method extracts
  the field data and writes it into the container.
  
  @param type expected type
  @param container field container
  @param id entity ID
  @param fixedData fixed data block
  @param varData var data block