{* ../../docs_src/openapi_callbacks/tutorial001.py hl[3,25] *}

### Create the callback *path operation* { #create-the-callback-path-operation }

To create the callback *path operation* use the same `APIRouter` you created above.

It should look just like a normal FastAPI *path operation*:

* It should probably have a declaration of the body it should receive, e.g. `body: InvoiceEvent`.

        // Time to live (2 bytes for v3)
        SMBUtil.writeInt2(300, buffer, 18);

        // DFS path offset (2 bytes) - points to string data
        SMBUtil.writeInt2(stringDataStart - 8, buffer, 20); // Offset from start of referral

        // DFS alternate path offset (2 bytes)
        SMBUtil.writeInt2(0, buffer, 22);

        // Network address offset (2 bytes)

 * This form is used in the admin API interface to upload files to the storage backend
 * with optional path specification for file organization.
 */
public class UploadForm {

    /**
     * The storage path where the file should be uploaded.
     * If not specified, the file will be stored in the default location.
     */
    public String path;

    /**
     * The multipart file to be uploaded to the storage system.

     */
    protected String getImageMimeType(final File imageFile) {
        final String path = imageFile.getAbsolutePath();
        if (path.endsWith(".png")) {
            return "image/png";
        }
        if (path.endsWith(".gif")) {
            return "image/gif";
        }
        if (path.endsWith(".jpg") || path.endsWith(".jpeg")) {
            return "image/jpeg";
        }

Swagger UI lo manejará detrás de escena para ti, pero necesita este auxiliar de "redirección".

///

### Crea una *path operation* para probarlo

Ahora, para poder probar que todo funciona, crea una *path operation*:

{* ../../docs_src/custom_docs_ui/tutorial001.py hl[36:38] *}

### Pruébalo

  # Load first party dynamic kernels.
  _tf_dir = _os.path.dirname(_current_file_location)
  _kernel_dir = _os.path.join(_tf_dir, "core", "kernels")
  if _os.path.exists(_kernel_dir):
    _ll.load_library(_kernel_dir)

  # Load third party dynamic kernels.
  for _s in _site_packages_dirs:
    _plugin_dir = _os.path.join(_s, "tensorflow-plugins")
    if _os.path.exists(_plugin_dir):
      _ll.load_library(_plugin_dir)

* host (in a podcast): host
* request (as in HTTP request): request
* response (as in HTTP response): response
* path operation function: path operation function (do not translate to "función de operación de ruta")
* path operation: path operation (do not translate to "operación de ruta")
* path (as in URL path): path (do not translate to "ruta")
* query (as in URL query): query (do not translate to "consulta")
* cookie (as in HTTP cookie): cookie

#   * -classpath
#   * -D...appname settings
#   * --module-path (only if needed)
#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.

# For Cygwin or MSYS, switch paths to Windows format before running java
if "$cygwin" || "$msys" ; then
    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )

    JAVACMD=$( cygpath --unix "$JAVACMD" )

    /**
     * Create a new directory cache entry
     *
     * @param path the directory path
     * @param key the lease key
     * @param scope the cache scope
     */
    public DirectoryCacheEntry(String path, Smb2LeaseKey key, DirectoryCacheScope scope) {
        this.directoryPath = path;
        this.leaseKey = key;
        this.scope = scope;
        this.createTime = System.currentTimeMillis();

  - virtual-environments.md
  - Tutorial - User Guide:
    - tutorial/index.md
    - tutorial/first-steps.md
    - tutorial/path-params.md
    - tutorial/query-params.md
    - tutorial/body.md
    - tutorial/query-params-str-validations.md
    - tutorial/path-params-numeric-validations.md
    - tutorial/query-param-models.md
    - tutorial/body-multiple-params.md
    - tutorial/body-fields.md