You can create production applications with **FastAPI** right now (and you have probably been doing it for some time), you just have to make sure that you use a version that works correctly with the rest of your code.

## Pin your `fastapi` version { #pin-your-fastapi-version }

{* ../../docs_src/custom_request_and_route/tutorial003_py310.py hl[26] *}

В этом примере *операции пути*, объявленные в `router`, будут использовать пользовательский класс `TimedRoute` и получат дополнительный HTTP-заголовок `X-Response-Time` в ответе с временем, затраченным на формирование ответа:

## Second dependency, "dependable" and "dependant" { #second-dependency-dependable-and-dependant }

Then you can create another dependency function (a "dependable") that at the same time declares a dependency of its own (so it is a "dependant" too):

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[13] *}

Let's focus on the parameters declared:

import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Type;
import java.lang.reflect.TypeVariable;
import java.sql.Time;
import java.sql.Timestamp;
import java.util.Collection;
import java.util.Map;

import org.codelibs.core.beans.BeanDesc;
import org.codelibs.core.beans.ParameterizedClassDesc;

These details are useful mainly if you had a FastAPI application older than 0.121.0 and you are facing issues with dependencies with `yield`.

///

Dependencies with `yield` have evolved over time to account for the different use cases and to fix some issues, here's a summary of what has changed.

### Dependencies with `yield` and `scope` { #dependencies-with-yield-and-scope }

pkg database/sql, type NullInt32 struct
pkg database/sql, type NullInt32 struct, Int32 int32
pkg database/sql, type NullInt32 struct, Valid bool
pkg database/sql, type NullTime struct
pkg database/sql, type NullTime struct, Time time.Time
pkg database/sql, type NullTime struct, Valid bool
pkg debug/dwarf, method (*UnsupportedType) Common() *CommonType
pkg debug/dwarf, method (*UnsupportedType) Size() int64

 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.opensearch.config.bsentity;

import java.time.LocalDateTime;
import java.util.HashMap;
import java.util.Map;

import org.codelibs.fess.opensearch.config.allcommon.EsAbstractEntity;
import org.codelibs.fess.opensearch.config.bsentity.dbmeta.FailureUrlDbm;

/**

This will skip the normal events such as DNS, connecting to the network, and downloading the response body.

As recommended by the HTTP RFC the max age of a document is defaulted to 10% of the 
document's age at the time it was served based on "Last-Modified". Default expiration dates aren't used for URIs 
containing a query.

 - CallStart
 - **CacheHit**
 - CallEnd
 
### Cache Miss

 * future version of {@code com.google.common.base.Supplier} will be made to <i>extend</i> {@code
 * java.util.function.Supplier}, making conversion code necessary only in one direction. At that
 * time, this interface will be officially discouraged.
 *
 * @author Harry Heymann
 * @since 2.0
 */
@GwtCompatible
public interface Supplier<T extends @Nullable Object> {
  /**

 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.opensearch.config.bsentity;

import java.time.LocalDateTime;
import java.util.HashMap;
import java.util.Map;

import org.codelibs.fess.opensearch.config.allcommon.EsAbstractEntity;
import org.codelibs.fess.opensearch.config.bsentity.dbmeta.BoostDocumentRuleDbm;