Before diving deeper into the **Dependency Injection** system, let's upgrade the previous example.

## A `dict` from the previous example { #a-dict-from-the-previous-example }

In the previous example, we were returning a `dict` from our dependency ("dependable"):

{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[9] *}

But then we get a `dict` in the parameter `commons` of the *path operation function*.

          if (labels[currentLabelIndex].size == currentLabelByteIndex) {
            // We've exhausted our current label. Either there are more labels to compare, in which
            // case we expect a dot as the next character. Otherwise, we've checked all our labels.
            if (currentLabelIndex == labels.size - 1) {
              break
            } else {
              currentLabelIndex++

   * to calling it exactly once.
   *
   * @since 10.0 (present in 1.0 as {@code run})
   */
  public void execute() {
    // Lock while we update our state so the add method above will finish adding any listeners
    // before we start to run them.
    RunnableExecutorPair list;
    synchronized (this) {
      if (executed) {
        return;
      }

import com.google.common.annotations.GwtCompatible;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

/**
 * Signifies that a test should not be run under Android. This annotation is respected only by our
 * Google-internal Android suite generators. Note that those generators also suppress any test
 * annotated with MediumTest or LargeTest.
 *
 * <p>For more discussion, see {@linkplain com.google.common.base.AndroidIncompatible the

import com.google.common.annotations.GwtCompatible;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

/**
 * Signifies that a test should not be run under Android. This annotation is respected only by our
 * Google-internal Android suite generators. Note that those generators also suppress any test
 * annotated with LargeTest.
 *
 * <p>For more discussion, see {@linkplain com.google.common.base.AndroidIncompatible the

   * of common.collect a second time with the results of the first compilation on the classpath. Or
   * just back this out once we stop doing that (which we'll do after our internal GWT setup
   * changes).
   */
  @Override
  public ImmutableMap<Object, Collection<Object>> asMap() {
    return super.asMap();
  }

  private Object readResolve() {

import com.google.common.annotations.GwtCompatible;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

/**
 * Signifies that a test should not be run under Android. This annotation is respected only by our
 * Google-internal Android suite generators. Note that those generators also suppress any test
 * annotated with LargeTest.
 *
 * <p>For more discussion, see {@linkplain com.google.common.base.AndroidIncompatible the

In our code example above, we don't use it directly, but we pass it to FastAPI for it to use it.

The `lifespan` parameter of the `FastAPI` app takes an **async context manager**, so we can pass our new `lifespan` async context manager to it.

{* ../../docs_src/events/tutorial003.py hl[22] *}

    mockWebServer.dispatcher = dispatcher
    val url = mockWebServer.url("/").toUrl()
    val conn = url.openConnection() as HttpURLConnection
    conn.responseCode // Force the connection to hit the "server".
    // Make sure our dispatcher got the request.
    assertThat(requestsMade.size).isEqualTo(1)
  }

  @Test
  fun outOfOrderResponses() {
    val firstResponseCode = AtomicInteger()
    val secondResponseCode = AtomicInteger()

  @CollectionFeature.Require(SERIALIZABLE)
  /*
   * As the class docs say, this test only makes sense for collections that define equals().
   * Accordingly, our testing framework adds it only when testing an implementation of List, Set, or
   * Multiset.
   */
  @SuppressWarnings("UndefinedEquals")
  public void testReserialize() {