} else if (collection instanceof Set) {
        return Collections.unmodifiableSet((Set<E>) collection);
      } else if (collection instanceof List) {
        return Collections.unmodifiableList((List<E>) collection);
      } else {
        return Collections.unmodifiableCollection(collection);
      }
    }

    @Override

      } else if (collection instanceof Set) {
        return Collections.unmodifiableSet((Set<E>) collection);
      } else if (collection instanceof List) {
        return Collections.unmodifiableList((List<E>) collection);
      } else {
        return Collections.unmodifiableCollection(collection);
      }
    }

    @Override

            final DefaultAuthenticationStrategy ntlmAuthStrategy = new DefaultAuthenticationStrategy() {
                private final List<String> schemePriority = Collections.unmodifiableList(Arrays.asList(StandardAuthScheme.BEARER,
                        StandardAuthScheme.DIGEST, StandardAuthScheme.NTLM, StandardAuthScheme.BASIC));

                @Override

            request = executionRequestPopulator.populateDefaults(request);

            BootstrapCoreExtensionManager resolver = container.lookup(BootstrapCoreExtensionManager.class);

            return Collections.unmodifiableList(resolver.loadCoreExtensions(request, providedArtifacts, extensions));

        } finally {
            executionRequestPopulator = null;
            container.dispose();
        }
    }