## Um aplicativo com callbacks

Vamos ver tudo isso com um exemplo.

Imagine que você tem um aplicativo que permite criar faturas.

Essas faturas terão um `id`, `title` (opcional), `customer` e `total`.

O usuário da sua API (um desenvolvedor externo) criará uma fatura em sua API com uma solicitação POST.

do FastAPI.

/// tip | Dica

Para perguntas, pergunte nas <a href="https://github.com/fastapi/fastapi/issues/new/choose" class="external-link" target="_blank">questões do GitHub</a>, lá tem um chance maior de você ser ajudado sobre o FastAPI [FastAPI Experts](fastapi-people.md#especialistas){.internal-link target=_blank}.

Use o chat apenas para outro tipo de assunto.

///

### Não faça perguntas no chat

import okhttp3.internal.connection.RealCall

/**
 * A concrete interceptor chain that carries the entire interceptor chain: all application
 * interceptors, the OkHttp core, all network interceptors, and finally the network caller.
 *
 * If the chain is for an application interceptor then [exchange] must be null. Otherwise it is for
 * a network interceptor and [exchange] must be non-null.
 */
class RealInterceptorChain(
  internal val call: RealCall,

/*
 * Copyright (C) 2007 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

/*
 * Copyright (C) 2021 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License

/*
 * Copyright (C) 2007 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

labels.wizard_button_finish=Pular
labels.search_list_configuration=Pesquisa
labels.search_list_button_delete=Excluir
labels.search_list_delete_confirmation=Tem certeza de que deseja excluí-lo?
labels.search_list_button_delete_all=Excluir tudo com esta consulta
labels.search_list_delete_all_confirmation=Tem certeza de que deseja excluir tudo com esta consulta?
labels.search_list_button_cancel=Cancelar
labels.failure_url_configuration=URL de falha

    void optionsMap_notMutated_verifyNoWrites() {
        // Arrange: create a regular map first, then spy on it
        Map<String, Object> originalMap = new HashMap<>();
        originalMap.put("refreshKrb5Config", "true");

        @SuppressWarnings("unchecked")
        Map<String, Object> spyOpts = spy(originalMap);

        // Reset the spy to clear any prior invocations from setup
        reset(spyOpts);

// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// but this fault is also not guaranteed.
func New[T any](a *Arena) *T {
	return runtime_arena_arena_New(a.a, reflectlite.TypeOf((*T)(nil))).(*T)
}

// MakeSlice creates a new []T with the provided capacity and length. The []T must
// not be used after the arena is freed. Accessing the underlying storage of the
// slice after free may result in a fault, but this fault is also not guaranteed.