# HTTP Basic Auth { #http-basic-auth }

For the simplest cases, you can use HTTP Basic Auth.

In HTTP Basic Auth, the application expects a header that contains a username and a password.

If it doesn't receive it, it returns an HTTP 401 "Unauthorized" error.

And returns a header `WWW-Authenticate` with a value of `Basic`, and an optional `realm` parameter.

That tells the browser to show the integrated prompt for a username and password.

/*
 * A nullable bound would let users create a TypeParameter instance for a parameter with a nullable
 * bound. However, it would also let them create `new TypeParameter<@Nullable T>() {}`, which
 * wouldn't behave as users might expect. Additionally, it's not clear how the TypeToken API could
 * support even a "normal" `TypeParameter<T>` when `<T>` has a nullable bound. (See the discussion

/*
 * Written by Doug Lea and Martin Buchholz with assistance from
 * members of JCP JSR-166 Expert Group and released to the public
 * domain, as explained at
 * http://creativecommons.org/publicdomain/zero/1.0/
 */

/*
 * Source:
 * http://gee.cs.oswego.edu/cgi-bin/viewcvs.cgi/jsr166/src/test/tck-jsr166e/AtomicDoubleArrayTest.java?revision=1.13
 * (Modified to adapt to guava coding conventions)
 */

package com.google.common.util.concurrent;

En el camino de la request, el middleware más externo se ejecuta primero.

En el camino de la response, se ejecuta al final.

Por ejemplo:

```Python
app.add_middleware(MiddlewareA)
app.add_middleware(MiddlewareB)

/*
 * Written by Doug Lea and Martin Buchholz with assistance from
 * members of JCP JSR-166 Expert Group and released to the public
 * domain, as explained at
 * http://creativecommons.org/publicdomain/zero/1.0/
 */

/*
 * Source:
 * http://gee.cs.oswego.edu/cgi-bin/viewcvs.cgi/jsr166/src/test/tck-jsr166e/AtomicDoubleArrayTest.java?revision=1.13
 * (Modified to adapt to guava coding conventions)
 */

package com.google.common.util.concurrent;

	// TODO(quasilyte): improve error message (#21860).
	VPGATHERQQ X2, (BP)(X20*2), X3  // ERROR "invalid instruction"
	VPGATHERQQ Y2, (BP)(Y20*2), Y3  // ERROR "invalid instruction"
	// YzrMulti4 expects exactly 4 registers referenced by REG_LIST.
	// TODO(quasilyte): improve error message (#21860).
	V4FMADDPS (AX), [Z0-Z4], K1, Z7  // ERROR "invalid instruction"
	V4FMADDPS (AX), [Z0-Z0], K1, Z7  // ERROR "invalid instruction"

  public void testSpliteratorUnknownOrder() {
    SpliteratorTester.of(collection::spliterator).expect(getSampleElements());
  }

  @CollectionFeature.Require(KNOWN_ORDER)
  public void testSpliteratorKnownOrder() {
    SpliteratorTester.of(collection::spliterator).expect(getOrderedElements()).inOrder();
  }

  @CollectionFeature.Require(ALLOWS_NULL_VALUES)
  @CollectionSize.Require(absent = ZERO)

```

### Things to know

- Fields such as `version` and `pools` are mandatory, however all other fields are optional.
- Each pool expects a minimum of 2 nodes per pool, and unique non-repeating hosts for each argument.
- Each pool expects each host in this pool has the same number of drives specified as any other host.

    python_bin="python"
  fi
  tfrun "$python_bin" tensorflow/tools/ci_build/update_version.py --nightly
  # replace tensorflow to tf_nightly in the wheel name
  export TFCI_BUILD_PIP_PACKAGE_WHEEL_NAME_ARG="$(echo $TFCI_BUILD_PIP_PACKAGE_WHEEL_NAME_ARG | sed 's/tensorflow/tf_nightly/')"
  export TFCI_BUILD_PIP_PACKAGE_ADDITIONAL_WHEEL_NAMES="$(echo $TFCI_BUILD_PIP_PACKAGE_ADDITIONAL_WHEEL_NAMES | sed 's/tensorflow/tf_nightly/g')"
fi

        lenient().when(mockAddress.getHostName()).thenReturn("WORKSTATION");
    }

    /**
     * Test case for when the 'Authorization' header is missing.
     * Expects the server to respond with a 'WWW-Authenticate: NTLM' header and a 401 status.
     * @throws IOException
     */
    @Test
    public void testAuthenticate_NoAuthorizationHeader() throws IOException {