from unicorn import UnicornMiddleware

app = FastAPI()

app.add_middleware(UnicornMiddleware, some_config="rainbow")
```

`app.add_middleware()` empfängt eine Middleware-Klasse als erstes Argument und dann alle weiteren Argumente, die an die Middleware übergeben werden sollen.

## Integrierte Middleware { #integrated-middlewares }

// are the same length and contain the same bytes.
// A nil argument is equivalent to an empty slice.
func Equal(a, b []byte) bool {
	// Neither cmd/compile nor gccgo allocates for these string conversions.
	return string(a) == string(b)
}

// Compare returns an integer comparing two byte slices lexicographically.
// The result will be 0 if a == b, -1 if a < b, and +1 if a > b.
// A nil argument is equivalent to an empty slice.

func generateCredentialStr(accessKey, date, region, service, requestVersion string) string {
	return "Credential=" + joinWithSlash(accessKey, date, region, service, requestVersion)
}

// joins the argument strings with a '/' and returns it.
func joinWithSlash(accessKey, date, region, service, requestVersion string) string {
	return strings.Join([]string{
		accessKey,
		date,
		region,
		service,
		requestVersion,

 *  Fix: Undo a performance regression introduced in OkHttp 4.0 caused by differences in behavior
    between Kotlin's `assert()` and Java's `assert()`. (Kotlin always evaluates the argument; Java
    only does when assertions are enabled.)

 *  Fix: Honor `RequestBody.isOneShot()` in `HttpLoggingInterceptor`.


## Version 4.2.2

_2019-10-06_

     * {@code mediaDrm::release}.
     *
     * @param closeable the object to be closed
     * @param closingExecutor the object will be closed on this executor
     * @return the first argument
     */
    @CanIgnoreReturnValue
    @ParametricNullness
    public <C extends @Nullable Object & @Nullable AutoCloseable> C eventuallyClose(
        @ParametricNullness C closeable, Executor closingExecutor) {

  }

  /**
   * Returns an array containing each value of {@code collection}, converted to a {@code short}
   * value in the manner of {@link Number#shortValue}.
   *
   * <p>Elements are copied from the argument collection as if by {@code collection.toArray()}.
   * Calling this method is as thread-safe as calling that method.
   *
   * @param collection a collection of {@code Number} instances

        // If the implementation uses identityHashCode(), referential equality is
        // probably intended. So no point in using an equal-but-different factory argument.
        // We check twice to avoid confusion caused by accidental hash collision.
        equalArgs.set(i, shouldBeEqualArg);
      }
    }
    return equalArgs;
  }

      }

      @Override
      @ParametricNullness
      public T next() {
        return iterator.next();
      }
    };
  }

  /**
   * Simply returns its argument.
   *
   * @deprecated no need to use this
   * @since 10.0
   */
  @InlineMe(
      replacement = "checkNotNull(iterator)",
      staticImports = "com.google.common.base.Preconditions.checkNotNull")

      }

      @Override
      @ParametricNullness
      public T next() {
        return iterator.next();
      }
    };
  }

  /**
   * Simply returns its argument.
   *
   * @deprecated no need to use this
   * @since 10.0
   */
  @InlineMe(
      replacement = "checkNotNull(iterator)",
      staticImports = "com.google.common.base.Preconditions.checkNotNull")

	f.Close()
	defer os.Remove(tmpFileName)

	// List of all tests for xlStorage initialization.
	testCases := []struct {
		name string
		err  error
	}{
		// Validates input argument cannot be empty.
		{
			"",
			errInvalidArgument,
		},
		// Validates if the directory does not exist and
		// gets automatically created.
		{
			tmpDirName,
			nil,
		},