* TypeVariable must have a different declaration or name. The only TypeVariable that our
         * new TypeVariable _will_ be equal to is an equivalent TypeVariable that was also created
         * by us. And that equality is guaranteed to hold because it doesn't involve the JDK
         * TypeVariable implementation at all.
         */

**FastAPI** provides a convenience tool to structure your application while keeping all the flexibility.

/// info

If you come from Flask, this would be the equivalent of Flask's Blueprints.

///

## An example file structure

Let's say you have a file structure like this:

```
.
├── app
│   ├── __init__.py
│   ├── main.py
│   ├── dependencies.py

```Python hl_lines="31  37"
{!> ../../docs_src/response_model/tutorial005.py!}
```

////

/// tip

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

It is equivalent to `set(["name", "description"])`.

///

#### Using `list`s instead of `set`s

If you forget to use a `set` and use a `list` or `tuple` instead, FastAPI will still convert it to a `set` and it will work correctly:

    return (ImmutableRangeSet<C>) EMPTY;
  }

  /**
   * Returns an immutable range set containing the specified single range. If {@link Range#isEmpty()
   * range.isEmpty()}, this is equivalent to {@link ImmutableRangeSet#of()}.
   */
  public static <C extends Comparable> ImmutableRangeSet<C> of(Range<C> range) {
    checkNotNull(range);
    if (range.isEmpty()) {
      return of();

   * @since 2.0
   */
  public static class Builder<K, V> extends ImmutableMap.Builder<K, V> {
    private final Comparator<? super K> comparator;

    /**
     * Creates a new builder. The returned builder is equivalent to the builder generated by {@link
     * ImmutableSortedMap#orderedBy}.
     */
    public Builder(Comparator<? super K> comparator) {
      this.comparator = checkNotNull(comparator);
    }

    /**

                   */
                  Set<Integer> unused = graph.successors(first);
                  return null;
                }
              }));
    }

    // For more about this test, see the equivalent in AbstractNetworkTest.
    for (Future<?> future : futures.build()) {
      future.get();
    }
    executor.shutdown();
  }

  private static final ImmutableSet<String> NO_PS =
      ImmutableSet.of("www", "foo.ihopethiswillneverbeapublicsuffix", "x.y.z");

  /**
   * Having a public suffix is equivalent to having a registry suffix, because all registry suffixes
   * are public suffixes, and all public suffixes have registry suffixes.
   */
  private static final ImmutableSet<String> NO_RS = NO_PS;

  /*
   * This is an implementation of ImmutableMap optimized especially for Android, which does not like
   * objects per entry.  Instead we use an open-addressed hash table.  This design is basically
   * equivalent to RegularImmutableSet, save that instead of having a hash table containing the
   * elements directly and null for empty positions, we store indices of the keys in the hash table,

    level = DeprecationLevel.ERROR,
  )
  fun receivedResponseAtMillis(): Long = receivedResponseAtMillis

  /**
   * Closes the response body. Equivalent to `body().close()`.
   *
   * Prior to OkHttp 5.0, it was an error to close a response that is not eligible for a body. This
   * includes the responses returned from [cacheResponse], [networkResponse], and [priorResponse].

   * 0} and {@code 2^32 - 1} inclusive.
   *
   * <p><b>Note:</b> this method is now unnecessary and should be treated as deprecated; use the
   * equivalent {@link Integer#compareUnsigned(int, int)} method instead.
   *
   * @param a the first unsigned {@code int} to compare
   * @param b the second unsigned {@code int} to compare