/// check | Revisa

Entonces, con la misma declaración de tipo de Python, **FastAPI** te ofrece validación de datos.

Nota que el error también indica claramente el punto exacto donde la validación falló.

Esto es increíblemente útil mientras desarrollas y depuras código que interactúa con tu API.

///

## Documentación

<img src="/img/tutorial/response-status-code/image01.png">

/// note | Nota

Algunos códigos de response (ver la siguiente sección) indican que el response no tiene un body.

FastAPI sabe esto, y producirá documentación OpenAPI que establece que no hay un response body.

///

## Acerca de los códigos de estado HTTP

/// note | Nota

    // The number of finalization rounds.
    private final int d;

    // Four 64-bit words of internal state.
    // The initial state corresponds to the ASCII string "somepseudorandomlygeneratedbytes",
    // big-endian encoded. There is nothing special about this value; the only requirement
    // was some asymmetry so that the initial v0 and v1 differ from v2 and v3.
    private long v0 = 0x736f6d6570736575L;

        // Act
        int bytesWritten = write.writeParameterWordsWireFormat(dst, 0);

        // Assert
        assertEquals(10, bytesWritten, "Should write 10 bytes");
        // Check FID (little-endian)
        assertEquals(0x34, dst[0] & 0xFF);
        assertEquals(0x12, dst[1] & 0xFF);
        // Check count
        assertEquals(10, dst[2] & 0xFF);
        assertEquals(0, dst[3] & 0xFF);
        // Check offset

/**
 * A {@link PrimitiveSink} that can compute a hash code after reading the input. Each hasher should
 * translate all multibyte values ({@link #putInt(int)}, {@link #putLong(long)}, etc) to bytes in
 * little-endian order.
 *
 * <p><b>Warning:</b> The result of calling any methods after calling {@link #hash} is undefined.
 *
 * <p><b>Warning:</b> Using a specific character encoding when hashing a {@link CharSequence} with

   * @param expectedCount the expected number of roundtrippable permutations
   * @param start the starting bytes encoded as a long as big-endian
   * @param lim the limit of bytes to process encoded as a long as big-endian, or -1 to mean the max
   *     limit for numBytes
   */
  @GwtIncompatible // java.nio.charset.Charset

        System.arraycopy(label, 0, suffix, 0, label.length);
        // + 1 byte 0x00
        // + context
        System.arraycopy(context, 0, suffix, label.length + 1, context.length);
        // + 4 byte (== r bits) big endian encoding of L
        suffix[suffix.length - 1] = (byte) 128;

        final DerivationParameters param = new KDFCounterParameters(sessionKey, null /* prefix */, suffix /* suffix */, r /* r */);
        gen.init(param);

        assertTrue(infoString.contains("bytesPerSect=512"), "toString should contain bytesPerSect");
    }

    // Helper methods to write numbers to byte array in little-endian format.
    private void writeInt2(int val, byte[] dst, int dstIndex) {
        dst[dstIndex++] = (byte) val;
        dst[dstIndex++] = (byte) (val >> 8);
    }

    checkArgument(
        result == (int) result,
        "the total number of elements (%s) in the arrays must fit in an int",
        result);
    return (int) result;
  }

  /**
   * Returns a big-endian representation of {@code value} in a 4-element byte array; equivalent to
   * {@code ByteBuffer.allocate(4).putInt(value).array()}. For example, the input value {@code

        Mac mac = Mac.getInstance("HmacMD5");
        MessageDigest md = MessageDigest.getInstance("MD5");
        mac.init(key);
        byte[] dk = mac.doFinal(MD5_CONSTANT);
        try {
            // little endian
            md.update((byte) (ms_usage & 0xFF));
            md.update((byte) (ms_usage >> 8 & 0xFF));
            md.update((byte) (ms_usage >> 16 & 0xFF));
            md.update((byte) (ms_usage >> 24 & 0xFF));