You can define those cases using a list in the type declaration.

You will receive all the values from the duplicate header as a Python `list`.

For example, to declare a header of `X-Token` that can appear more than once, you can write:

{* ../../docs_src/header_params/tutorial003_an_py310.py hl[9] *}

If you communicate with that *path operation* sending two HTTP headers like:

```
X-Token: foo
X-Token: bar
```

            new Function<AnEnum, AnEnum>() {
              boolean used = false;

              @Override
              public AnEnum apply(AnEnum ae) {
                checkState(!used, "should not be applied more than once");
                used = true;
                return ae;
              }
            });
    ImmutableMap<AnEnum, AnEnum> copy = Maps.immutableEnumMap(map);

 * These types influence various aspects of the build lifecycle, such as which plugins are executed and how dependencies are managed.</p>
 *
 * <p>The {@code Packaging} class is an immutable value object, ensuring that once a packaging type is defined, it cannot be changed.</p>
 *
 * <h2>Standard Packaging Types</h2>
 * <ul>
 *     <li>{@code jar}: Packages the project as a Java Archive (JAR) file.</li>

        when(supplier.get()).thenThrow(new RuntimeException(new SmbUnsupportedOperationException("boom")));

        // Act & Assert: the exception is propagated and interaction recorded once
        RuntimeException thrown = assertThrows(RuntimeException.class, supplier::get);
        assertInstanceOf(SmbUnsupportedOperationException.class, thrown.getCause());
        assertEquals("boom", thrown.getCause().getMessage());

    private static SingletonContext INSTANCE;

    /**
     * Initialize singleton context using custom properties
     *
     * This method can only be called once.
     *
     * @param props the properties to use for initialization
     * @throws CIFSException if the singleton context is already initialized or there is an error during initialization
     */

import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * A {@link Future} that accepts completion listeners. Each listener has an associated executor, and
 * it is invoked using this executor once the future's computation is {@linkplain Future#isDone()
 * complete}. If the computation has already completed when the listener is added, the listener will
 * execute immediately.
 *
 * <p>See the Guava User Guide article on <a

import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * A {@link Future} that accepts completion listeners. Each listener has an associated executor, and
 * it is invoked using this executor once the future's computation is {@linkplain Future#isDone()
 * complete}. If the computation has already completed when the listener is added, the listener will
 * execute immediately.
 *
 * <p>See the Guava User Guide article on <a

*Yol operasyonları* sıralı bir şekilde gözden geçirildiğinden dolayı `/users/me` yolunun `/users/{user_id}` yolundan önce tanımlanmış olmasından emin olmanız gerekmektedir:

{* ../../docs_src/path_params/tutorial003.py hl[6,11] *}

    }

    @Override
    @ParametricNullness
    // We set the field only once (during construction or deserialization).
    @SuppressWarnings("SynchronizeOnNonFinalField")
    public T get() {
      // Another variant of Double Checked Locking.
      //
      // We use two volatile reads. We could reduce this to one by
      // putting our fields into a holder class, but (at least on x86)

        // multiple elements already available (e.g. LinkedBlockingQueue#drainTo locks only once)
        added += q.drainTo(buffer, numElements - added);
        if (added < numElements) { // not enough elements immediately available; will have to poll
          E e; // written exactly once, by a successful (uninterrupted) invocation of #poll
          while (true) {
            try {