private Class<?> useOffer(String className, ClassLoaderOffer offer) {
    try {
      if (offer == null) {
        log.severe(
            "Failed to use code to resolve class " + className + " as there's no offer provided.");
        return null;
      }
      Class<?> requestedClass = null;
      // we go through all files in this offer and register them within this classloader
      for (ClassLoaderFile file : offer.getFiles()) {
        switch (file.getType()) {
          case CLASS:
            if (super.findLoadedClass(file.getName()) != null) {
              log.info("Attempting to load already loaded class: " + file.getName());
              continue;
            }

            byte[] bytecode = file.getContent();
            if (bytecode
                == null) // if there's no content in transmitted file, we have to get it from the
                         // cache.
            bytecode = cache.getClassBytecode(file.getName(), offer.getName());

            if (bytecode == null) {
              log.severe(
                  "Failed to define class " + file.getName() + " from offer " + offer.getName());
              continue;
            }

            Class<?> clazz = defineClass(file.getName(), bytecode, 0, bytecode.length);
            if (clazz.getName().equals(className)) requestedClass = clazz;

            break;

          case JAR:
            String path = cache.getFileLocation(file.getName(), offer.getName());

            if (path == null) {
              log.severe(
                  "Failed to find file " + file.getName() + " from package " + offer.getName());
              continue;
            }

            try {
              addURL(new File(path).toURI().toURL());
            } catch (MalformedURLException e) {
              log.severe("Exception while registering file " + path + ":" + e.toString());
              continue;
            }
            break;

          case ROFILE:
            //					case RWFILE:
            if (!cache.deployFile(file.getName(), offer.getName()))
              log.severe(
                  "Failed to deploy required file "
                      + file.getName()
                      + ". Failed to write file to disk.");
            break;

          default:
            log.severe(
                "Unexpected type of file ("
                    + file.getType()
                    + ") provided in the offer. skipping.");
        }
      }

      if (className != null
          && requestedClass
              == null) { // this can happen as it is possible that the required class is in the jar
        byte[] bytecode = cache.getClassBytecode(className, offer.getName());
        if (bytecode != null) requestedClass = defineClass(className, bytecode, 0, bytecode.length);
      }

      usedOffers.add(offer.getName()); // if everything is fine, we add this offer as used.

      return requestedClass;
    } catch (Throwable ex) {
      log.severe(
          "Failed to use offer "
              + (offer != null ? offer.getName() : "NULL offer ")
              + " from the cache. Removing the offer and failing...");

      if (offer != null) cache.removeOfferByName(offer.getName());

      throw ex;
    }
  }
  /** Checks whether list of files contains file with the same name as proposed. */
  private boolean containsFile(List<ClassLoaderFile> filesList, ClassLoaderFile otherFile) {
    for (ClassLoaderFile file : filesList)
      if (file.getName().equals(otherFile.getName())) return true;

    return false;
  }