## Create a middleware

To create a middleware you use the decorator `@app.middleware("http")` on top of a function.

The middleware function receives:

* The `request`.
* A function `call_next` that will receive the `request` as a parameter.
    * This function will pass the `request` to the corresponding *path operation*.
    * Then it returns the `response` generated by the corresponding *path operation*.

import com.google.common.annotations.GwtCompatible;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A class that can supply objects of a single type; a pre-Java-8 version of {@link
 * java.util.function.Supplier java.util.function.Supplier}. Semantically, this could be a factory,
 * generator, builder, closure, or something else entirely. No guarantees are implied by this
 * interface.
 *

   * {@code function} to the argument, then evaluating using {@code this}. That is, for any pair of
   * non-null objects {@code x} and {@code y}, {@code equivalence.onResultOf(function).equivalent(a,
   * b)} is true if and only if {@code equivalence.equivalent(function.apply(a), function.apply(b))}
   * is true.
   *
   * <p>For example:
   *
   * <pre>{@code

 */
package org.codelibs.core.stream;

import java.util.Arrays;
import java.util.Collections;
import java.util.Map;
import java.util.function.Consumer;
import java.util.function.Function;
import java.util.function.Supplier;
import java.util.stream.Stream;

public class StreamUtil {
    private StreamUtil() {
        // nothing
    }

    @SafeVarargs

                Set.of("QUERY1", "QUERY2"), //
                buildQuery("QUERY1^10 QUERY2^5"));

        assertQueryContext(

    final BarChild barChild = new BarChild();
    Function<Foo, BarChild> function =
        new Function<Foo, BarChild>() {
          @Override
          public BarChild apply(Foo unused) {
            return barChild;
          }
        };
    Bar bar = getDone(transform(future, function, directExecutor()));
    assertSame(barChild, bar);
  }

  /*

        functionCall: FirFunctionCall,
        mode: KtConstantEvaluationMode,
    ): FirLiteralExpression<*>? {
        val function = functionCall.getOriginalFunction() as? FirSimpleFunction ?: return null

        val opr1 = evaluate(functionCall.explicitReceiver, mode) ?: return null
        opr1.evaluate(function)?.let {
            return it.adjustType(functionCall.resolvedType)
        }

import java.io.ObjectInputStream;
import java.io.Serializable;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.function.BinaryOperator;
import java.util.function.Function;
import java.util.stream.Collector;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**

[ -n "$BASH_XTRACEFD" ] && set -x

function _init() {
	## All binaries are static make sure to disable CGO.
	export CGO_ENABLED=0

	## List of architectures and OS to test coss compilation.
	SUPPORTED_OSARCH="linux/ppc64le linux/mips64 linux/amd64 linux/arm64 linux/s390x darwin/arm64 darwin/amd64 freebsd/amd64 windows/amd64 linux/arm linux/386 netbsd/amd64 linux/mips openbsd/amd64"
}

function _build() {
	local osarch=$1

# Response Model - Return Type

You can declare the type used for the response by annotating the *path operation function* **return type**.

You can use **type annotations** the same way you would for input data in function **parameters**, you can use Pydantic models, lists, dictionaries, scalar values like integers, booleans, etc.

=== "Python 3.10+"

    ```Python hl_lines="16  21"
    {!> ../../../docs_src/response_model/tutorial001_01_py310.py!}
    ```