code: public D get(E el, P pseudo)
      {
          D ret;
          if (pseudo == null)
              ret = mainMap.get(el);
          else
          {
          	HashMap<P, D> map = pseudoMaps.get(el);
              if (map == null)
                  ret = null;
              else
                  ret = map.get(pseudo);
          }
          return ret;
      }
docs: Gets the data for the given element and pseudo-element.
  @param el the element
  @param pseudo a pseudo-element or null, if no pseudo-element is required
  @return the stored data