code: Stream<ClassBytecodes> classesToLoad(List<String> classnames) {
          toRedefine = new ArrayList<>();
          List<ClassBytecodes> toLoad = new ArrayList<>();
          if (status.isDefined() && !isImport()) {
              // Classes should only be loaded/redefined if the compile left them
              // in a defined state.  Imports do not have code and are not loaded.
              for (String cn : classnames) {
                  ClassInfo ci = state.classTracker.get(cn);
                  if (ci.isLoaded()) {
                      if (ci.isCurrent()) {
                          // nothing to do
                      } else {
                          toRedefine.add(ci);
                      }
                  } else {
                      // If not loaded, add to the list of classes to load.
                      toLoad.add(ci.toClassBytecodes());
                      dependenciesNeeded = true;
                  }
              }
          }
          return toLoad.stream();
      }
docs: Process the class information from the last compile. Requires loading of
  returned list.
  
  @return the list of classes to load