code: public List<ContainerData> selectJars(ContainerData targetContainerData) throws ClassSource_Exception {
          List<ContainerData> jarContainers = new ArrayList<ContainerData>();
  
          // A null target container means than an explicitly
          // specified container was not located.  That is an error.
  
          Container targetContainer = targetContainerData.container;
          if (targetContainer == null) {
              throw new ClassSource_Exception("Container [ " + targetContainerData.name + " ] was not resolved");
          }
  
          for (Entry nextEntry : targetContainerData.container) {
              String nextEntryName = nextEntry.getName();
              if (!nextEntryName.toUpperCase().endsWith(".JAR")) {
                  continue; // The targets MUST have the ".jar" extension.
              }
  
              try {
                  Container nextContainer = nextEntry.adapt(Container.class);
                  if (nextContainer == null) {
                      continue; // TODO: This should be an error
                  }
  
                  ContainerData nextContainerData =
                                  new ContainerData(targetContainerData.name + " to " + nextEntryName, nextContainer);
  
                  jarContainers.add(nextContainerData);
              } catch (UnableToAdaptException e) {
                  throw new ClassSource_Exception("JAR select [ " + nextEntryName + " ] could not be used as a container: " + e);
              }
          }
  
          return jarContainers;
      }
docs: TODO: This must recurse!