{* ../../docs_src/sql_databases/tutorial001_an_py310.py ln[21:22] hl[21:22] *}

### Create a Session Dependency { #create-a-session-dependency }

A **`Session`** is what stores the **objects in memory** and keeps track of any changes needed in the data, then it **uses the `engine`** to communicate with the database.

  - A namespaced object with an ownerReference referencing a uid of a namespaced kind which does not exist in the same namespace is now consistently treated as though that owner does not exist, and the child object is deleted.

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Arrays;
import java.util.Objects;
import java.util.function.Consumer;
import java.util.logging.Logger;

import static org.codelibs.curl.io.ContentOutputStream.PREFIX;
import static org.codelibs.curl.io.ContentOutputStream.SUFFIX;

/// note | Technical Details

Actually, `Query`, `Path` and others you'll see next create objects of subclasses of a common `Param` class, which is itself a subclass of Pydantic's `FieldInfo` class.

And Pydantic's `Field` returns an instance of `FieldInfo` as well.

`Body` also returns objects of a subclass of `FieldInfo` directly. And there are others you will see later that are subclasses of the `Body` class.

`UploadFile` hat die folgenden `async`hronen Methoden. Sie alle rufen die entsprechenden Methoden des darunterliegenden Datei-Objekts auf (wobei intern `SpooledTemporaryFile` verwendet wird).

  /**
   * For <a href="https://tools.ietf.org/html/rfc7515">JWS or JWE objects using the Compact
   * Serialization</a>.
   *
   * @since 27.1
   */
  public static final MediaType JOSE = createConstant(APPLICATION_TYPE, "jose");

  /**
   * For <a href="https://tools.ietf.org/html/rfc7515">JWS or JWE objects using the JSON
   * Serialization</a>.
   *
   * @since 27.1
   */

    QUEUING,
    /** runnable has been submitted but has not yet begun execution */
    QUEUED,
    RUNNING,
  }

  /** Underlying executor that all submitted Runnable objects are run on. */
  private final Executor executor;

  @GuardedBy("queue")
  private final Deque<Runnable> queue = new ArrayDeque<>();

  /** see {@link WorkerRunningState} */
  @LazyInit
  @GuardedBy("queue")

import org.xml.sax.helpers.DefaultHandler;

/**
 * Parser for Google Search Appliance (GSA) configuration files.
 * This SAX-based parser reads GSA XML configuration files and converts them into
 * Fess configuration objects including web crawling configurations, file crawling
 * configurations, and label types for access control.
 *
 * <p>The parser handles the following GSA configuration elements:
 * <ul>

// since most usage will be by language specific wrappers.
//
// Conventions:
// * We use the prefix TF_ for everything in the API.
// * Objects are always passed around as pointers to opaque structs
//   and these structs are allocated/deallocated via the API.
// * TF_Status holds error information.  It is an object type
//   and therefore is passed around as a pointer to an opaque
//   struct as mentioned above.

    /**
     * Logs a message using the provided LogHelper.
     * @param logHelper The LogHelper instance.
     * @param key The LogType key.
     * @param objs The objects to log.
     */
    protected void log(final LogHelper logHelper, final LogType key, final Object... objs) {
        if (logHelper != null) {
            logHelper.log(key, objs);
        }
    }

    /**