Object key = new Object();
    assertThat(cache.getUnchecked(key)).isSameInstanceAs(computed);
    RemovalNotification<Object, Object> notification = listener.remove();
    assertThat(notification.getKey()).isSameInstanceAs(key);
    assertThat(notification.getValue()).isSameInstanceAs(computed);
    assertThat(notification.getCause()).isEqualTo(RemovalCause.SIZE);
    assertThat(listener.isEmpty()).isTrue();
    checkEmpty(cache);
  }

    Object key = new Object();
    assertThat(cache.getUnchecked(key)).isSameInstanceAs(computed);
    RemovalNotification<Object, Object> notification = listener.remove();
    assertThat(notification.getKey()).isSameInstanceAs(key);
    assertThat(notification.getValue()).isSameInstanceAs(computed);
    assertThat(notification.getCause()).isEqualTo(RemovalCause.SIZE);
    assertThat(listener.isEmpty()).isTrue();
    checkEmpty(cache);
  }

  static class QueuingRemovalListener<K, V> extends ConcurrentLinkedQueue<RemovalNotification<K, V>>
      implements RemovalListener<K, V> {

    @Override
    public void onRemoval(RemovalNotification<K, V> notification) {
      add(notification);
    }
  }

  /**
   * {@link RemovalListener} that counts each {@link RemovalNotification} it receives, and provides
   * access to the most-recently received one.
   */

            content = f"notification for {email}: {message}"
            email_file.write(content)


    @app.post("/send-notification/{email}")
    async def send_notification(email: str, background_tasks: BackgroundTasks):
        background_tasks.add_task(write_notification, email, message="some notification")
        return {"message": "Notification sent in the background"}
    ```
    """

    if log.is_file():
        os.remove(log)  # pragma: no cover
    response = client.post("/send-notification/******@****.***")
    assert response.status_code == 200, response.text
    assert response.json() == {"message": "Notification sent in the background"}
    with open("./log.txt") as f:

    with open("log.txt", mode="w") as email_file:
        content = f"notification for {email}: {message}"
        email_file.write(content)


@app.post("/send-notification/{email}")
async def send_notification(email: str, background_tasks: BackgroundTasks):
    background_tasks.add_task(write_notification, email, message="some notification")

    * Collect the money from the client.
    * Send a notification back to the API user (the external developer), as a callback.
        * At this point is that the API will somehow send a POST request to the
            external API with the notification of the invoice event
            (e.g. "payment successful").
    """
    # Send the invoice, collect the money, send the notification (the callback)

  static class QueuingRemovalListener<K, V> extends ConcurrentLinkedQueue<RemovalNotification<K, V>>
      implements RemovalListener<K, V> {

    @Override
    public void onRemoval(RemovalNotification<K, V> notification) {
      add(notification);
    }
  }

  /**
   * {@link RemovalListener} that counts each {@link RemovalNotification} it receives, and provides
   * access to the most-recently received one.
   */

    * Collect the money from the client.
    * Send a notification back to the API user (the external developer), as a callback.
        * At this point is that the API will somehow send a POST request to the
            external API with the notification of the invoice event
            (e.g. "payment successful").
    """
    # Send the invoice, collect the money, send the notification (the callback)
    return {"msg": "Invoice received"}

 * the License.
 */

package com.google.common.cache;

import com.google.common.annotations.GwtCompatible;

/**
 * An object that can receive a notification when an entry is removed from a cache. The removal
 * resulting in notification could have occurred to an entry being manually removed or replaced, or
 * due to eviction resulting from timed expiration, exceeding a maximum size, or garbage collection.
 *