This also applies to `response_model_by_alias` that works similarly.

///

{* ../../docs_src/response_model/tutorial005_py310.py hl[29,35] *}

/// tip

The syntax `{"name", "description"}` creates a `set` with those two values.

description: A collection of common/useful code examples for Kotlin and Java
---


# Recipes

We've written some recipes that demonstrate how to solve common problems with OkHttp. Read through them to learn about how everything works together. Cut-and-paste these examples freely; that's what they're for.

### Synchronous Get ([.kt][SynchronousGetKotlin], [.java][SynchronousGetJava])

Download a file, print its headers, and print its response body as a string.

   * requested permits, by an invocation acquire(permits), are served from:
   *
   * - stored permits (if available)
   *
   * - fresh permits (for any remaining permits)
   *
   * How this works is best explained with an example:
   *
   * For a RateLimiter that produces 1 token per second, every second that goes by with the
   * RateLimiter being unused, we increase storedPermits by 1. Say we leave the RateLimiter unused

    public String toString() {
      return "BY_TO_STRING";
    }

    private Object readResolve() {
      return INSTANCE;
    }
  }

  // Always equal is a valid total ordering. And it works for any Object.
  private static final class AlwaysEqual extends Ordering<@Nullable Object>
      implements Serializable {
    private static final AlwaysEqual INSTANCE = new AlwaysEqual();

    @Override

// decreasing precedence:
//
// 1. the value of the corresponding environment variable if set,
// 2. the value of the parameter in the config store if set,
// 3. the default value,
//
// This function only works for a subset of sub-systems, others return
// `ValueSourceAbsent`. FIXME: some parameters have custom environment
// variables for which support needs to be added.
//

I think `Union[SomeType, None]` is more explicit about what it means.

It's just about the words and names. But those words can affect how you and your teammates think about the code.

As an example, let's take this function:

{* ../../docs_src/python_types/tutorial009c_py39.py hl[1,4] *}

You can check it at <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>:

<img src="/img/tutorial/behind-a-proxy/image01.png">

But if we access the docs UI at the "official" URL using the proxy with port `9999`, at `/api/v1/docs`, it works correctly! 🎉

   */
  @CanIgnoreReturnValue // pushed down from class to method
  @Override
  public Iterator<E> iterator() {
    return new Itr(toArray());
  }

  /** Snapshot iterator that works off copy of underlying q array. */
  private class Itr implements Iterator<E> {
    final Object[] array; // Array of all elements
    int cursor; // index of next element to return;

       * Well, really, we use this when we think we're running under Java 8, as determined by some
       * logic in the static initializer, which does not check for getTypeName specifically. We
       * should really validate that it works as desired for all Android versions that we support.
       */
      @SuppressWarnings("NewApi")
      @Override
      String typeName(Type type) {
        return type.getTypeName();
      }
    },

    }

    @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 0;
  }

  /**
   * Quasi-implementation of {@link ListIterator} that works from a list of elements and a set of
   * features to support (from the enclosing {@link AbstractIteratorTester} instance). Instead of
   * throwing exceptions like {@link NoSuchElementException} at the appropriate times, it throws