code: @Override
      public T addAsLibrary(URL resource, ArchivePath target) throws IllegalArgumentException {
          Validate.notNull(resource, "Resource must be specified");
          Validate.notNull(target, "Target must be specified");
  
          File resourceFile = new File(resource.getFile());
          if (!resourceFile.exists()) {
              return addAsLibrary(new UrlAsset(resource), target);
          }
  
          if (resourceFile.isFile()) {
              return addAsLibrary(new UrlAsset(resource), target);
          }
  
          if (resourceFile.listFiles().length == 0) {
              return addAsLibrary(new UrlAsset(resource), target);
          }
  
          for (File file : resourceFile.listFiles()) {
              addAsLibrary(file, new BasicPath(target, file.getName()));
          }
  
          return covarientReturn();
      }
docs: /*
  (non-Javadoc)
  
  @see org.jboss.shrinkwrap.api.container.LibraryContainer#addLibrary(java.net.URL, org.jboss.shrinkwrap.api.Path)