* For `PUT` requests to `/items/{item_id}`, read the body as JSON:
    * Check that it has a required attribute `name` that should be a `str`.
    * Check that it has a required attribute `price` that has to be a `float`.
    * Check that it has an optional attribute `is_offer`, that should be a `bool`, if present.
    * All this would also work for deeply nested JSON objects.

        by_alias: bool = True,
        exclude_unset: bool = False,
        exclude_defaults: bool = False,
        exclude_none: bool = False,
    ) -> Any:
        # What calls this code passes a value that already called
        # self._type_adapter.validate_python(value)
        return self._type_adapter.dump_python(
            value,
            mode=mode,
            include=include,

Esse sistema foi pensado para ser fácil de usar, e permitir que qualquer desenvolvedor possa integrar facilmente outros componentes ao **FastAPI**.

## O que é "Injeção de Dependência" { #what-is-dependency-injection }

  //   spinning, so we use SPIN_THRESHOLD_NANOS which is what AbstractQueuedSynchronizer uses for
  //   similar purposes.
  // * We want to behave reasonably for timeouts of 0
  // * We are more responsive to completion than timeouts. This is because parkNanos depends on
  //   system scheduling and as such we could either miss our deadline, or unpark() could be delayed

That information is available in the app's **OpenAPI schema**, and then shown in the API docs.

That same information from the models that is included in OpenAPI is what can be used to **generate the client code**.

### Hey API { #hey-api }

Once we have a FastAPI app with the models, we can use Hey API to generate a TypeScript client. The fastest way to do that is via npx.

```sh

Está diseñado para ser muy simple de usar, y para hacer que cualquier desarrollador integre otros componentes con **FastAPI** de forma muy sencilla.

## Qué es la "Inyección de Dependencias" { #what-is-dependency-injection }

    // call get() twice to make sure that memoization doesn't interfere
    // with throwing the exception
    for (int i = 0; i < 2; i++) {
      try {
        memoizedSupplier.get();
        fail("failed to throw NullPointerException");
      } catch (NullPointerException e) {
        // this is what should happen
      }
    }
  }

  @J2ktIncompatible

    // call get() twice to make sure that memoization doesn't interfere
    // with throwing the exception
    for (int i = 0; i < 2; i++) {
      try {
        memoizedSupplier.get();
        fail("failed to throw NullPointerException");
      } catch (NullPointerException e) {
        // this is what should happen
      }
    }
  }

  @J2ktIncompatible

   * absent, it will fall back to a heavyweight operation that will open a stream, read (or {@link
   * InputStream#skip(long) skip}, if possible) to the end of the stream and return the total number
   * of bytes that were read.
   *
   * <p>Note that for some sources that implement {@link #sizeIfKnown} to provide a more efficient
   * implementation, it is <i>possible</i> that this method will return a different number of bytes

// It returns (0, io.EOF) when it reaches the end of that file,
// until [Next] is called to advance to the next file.
//
// If the current file is sparse, then the regions marked as a hole
// are read back as NUL-bytes.
//
// Calling Read on special types like [TypeLink], [TypeSymlink], [TypeChar],
// [TypeBlock], [TypeDir], and [TypeFifo] returns (0, [io.EOF]) regardless of what
// the [Header.Size] claims.