assertEquals("b", iterator.previous());
    assertThrows(UnsupportedOperationException.class, () -> iterator.add("c"));
  }

  @SuppressWarnings("DoNotCall")
  public void testSet() {
    ListIterator<String> iterator = create();

    assertTrue(iterator.hasNext());
    assertEquals("a", iterator.next());
    assertEquals("b", iterator.next());
    assertEquals("b", iterator.previous());

    return (MinimalIterable) of(elements.toArray());
  }

  private @Nullable Iterator<E> iterator;

  private MinimalIterable(Iterator<E> iterator) {
    this.iterator = iterator;
  }

  @Override
  public Iterator<E> iterator() {
    if (iterator == null) {
      // TODO: throw something else? Do we worry that people's code and tests

     *
     * @param bytes number of bytes sent
     * @param durationNanos operation duration in nanoseconds
     */
    public void recordRdmaSend(int bytes, long durationNanos) {
        rdmaSends.incrementAndGet();
        bytesTransferred.addAndGet(bytes);
        totalSendTime.addAndGet(durationNanos);
    }

    /**
     * Record an RDMA receive operation
     *

    bimap.put(1, "one");
    bimap.put(2, "two");
    bimap.put(3, "three");
    Iterator<Integer> iterator = bimap.keySet().iterator();
    iterator.next();
    iterator.next();
    iterator.remove();
    iterator.next();
    iterator.remove();
    assertEquals(1, bimap.size());
    assertEquals(1, bimap.inverse().size());
  }

    Iterator<String> iterator = skip(list, 2).iterator();
    assertThrows(IllegalStateException.class, () -> iterator.remove());
  }

  public void testSkip_allOfImmutableList_modifiable() {
    List<String> list = ImmutableList.of("a", "b");
    Iterator<String> iterator = skip(list, 2).iterator();
    assertThrows(UnsupportedOperationException.class, () -> iterator.remove());
  }

/**
 * Represents the response of a suggest delete operation.
 * This class contains information about any errors that occurred during the operation
 * and the time taken to complete the operation.
 */
public class SuggestDeleteResponse {
    /** List of errors that occurred during the operation. */
    protected final List<Throwable> errors = new ArrayList<>();
    /** Time taken for the operation in milliseconds. */
    protected final long took;

        @Override
        public @Nullable Object execute(Iterator<?> iterator) {
          iterator.remove();
          return null;
        }
      };

  private static final IteratorOperation NEXT_METHOD =
      new IteratorOperation() {
        @Override
        public @Nullable Object execute(Iterator<?> iterator) {
          return iterator.next();
        }
      };

```

...that's because the client generator uses the OpenAPI internal **operation ID** for each *path operation*.

OpenAPI requires that each operation ID is unique across all the *path operations*, so FastAPI uses the **function name**, the **path**, and the **HTTP method/operation** to generate that operation ID, because that way it can make sure that the operation IDs are unique.

But I'll show you how to improve that next. 🤓

![Swagger UI interaction](https://fastapi.tiangolo.com/img/index/index-04-swagger-03.png)

* Then click on the "Execute" button, the user interface will communicate with your API, send the parameters, get the results and show them on the screen:

![Swagger UI interaction](https://fastapi.tiangolo.com/img/index/index-05-swagger-04.png)

## Resumo e Descrição da documentação - OpenAPI