# Including WSGI - Flask, Django, others

You can mount WSGI applications as you saw with [Sub Applications - Mounts](sub-applications.md){.internal-link target=_blank}, [Behind a Proxy](behind-a-proxy.md){.internal-link target=_blank}.

For that, you can use the `WSGIMiddleware` and use it to wrap your WSGI application, for example, Flask, Django, etc.

## Using `WSGIMiddleware`

You need to import `WSGIMiddleware`.

import org.junit.Ignore;

/**
 * Basic reserialization test for collection types that must preserve {@code equals()} behavior when
 * reserialized. (Sets and Lists, but not bare Collections.)
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
public class CollectionSerializationEqualTester<E> extends AbstractCollectionTester<E> {

import java.util.Arrays;
import org.junit.Ignore;

/**
 * Tests for {@code Multiset.containsAll} not already addressed by {@code CollectionContainsTester}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
public class MultisetContainsTester<E> extends AbstractMultisetTester<E> {

import java.util.Collection;
import java.util.Map.Entry;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Creates multimaps, containing sample elements, to be tested.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public interface TestMultimapGenerator<
        K extends @Nullable Object, V extends @Nullable Object, M extends Multimap<K, V>>

import com.google.common.annotations.J2ktIncompatible;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;

/**
 * An {@link InputStream} that counts the number of bytes read.
 *
 * @author Chris Nokleberg
 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public final class CountingInputStream extends FilterInputStream {

import com.google.common.annotations.GwtCompatible;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A supertype for filtered {@link SetMultimap} implementations.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
interface FilteredSetMultimap<K extends @Nullable Object, V extends @Nullable Object>
    extends FilteredMultimap<K, V>, SetMultimap<K, V> {
  @Override

 * are annotated or abstract in the superclass.
 *
 * <p>This test must be outside the c.g.c.eventbus package to test correctly.
 *
 * @author Louis Wasserman
 */
abstract class AbstractEventBusTest<H> extends TestCase {
  static final Object EVENT = new Object();

  abstract H createSubscriber();

  private @Nullable H subscriber;

  H getSubscriber() {

   *     values.
   */
  @Deprecated
  public static double mean(int... values) {
    checkArgument(values.length > 0, "Cannot take mean of 0 values");
    // The upper bound on the length of an array and the bounds on the int values mean that, in
    // this case only, we can compute the sum as a long without risking overflow or loss of
    // precision. So we do that, as it's slightly quicker than the Knuth algorithm.
    long sum = 0;

import com.google.common.annotations.J2ktIncompatible;
import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.OutputStream;

/**
 * An OutputStream that counts the number of bytes written.
 *
 * @author Chris Nokleberg
 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public final class CountingOutputStream extends FilterOutputStream {

/**
 * An iterator that transforms a backing iterator; for internal use. This avoids the object overhead
 * of constructing a {@link com.google.common.base.Function Function} for internal methods.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
abstract class TransformedIterator<F extends @Nullable Object, T extends @Nullable Object>
    implements Iterator<T> {