(For example, a function in a library to compute square roots has
    a purpose that is entirely well-defined independent of the
    application.  Therefore, Subsection 2d requires that any
    application-supplied function or table used by this function must
    be optional: if the application does not supply it, the square
    root function must still compute square roots.)

In this case, the task function will write to a file (simulating sending an email).

And as the write operation doesn't use `async` and `await`, we define the function with normal `def`:

{* ../../docs_src/background_tasks/tutorial001.py hl[6:9] *}

## Add the background task

   * exception (typically, but not necessarily, {@link IllegalArgumentException}).
   *
   * <p>The returned converter is serializable if both provided functions are.
   *
   * @since 17.0
   */
  public static <A, B> Converter<A, B> from(
      Function<? super A, ? extends B> forwardFunction,
      Function<? super B, ? extends A> backwardFunction) {

	case e.DateDiff != nil:
		return sqlFnDateDiff
	default:
		return ""
	}
}

// evalSQLFnNode assumes that the FuncExpr is not an aggregation
// function.
func (e *FuncExpr) evalSQLFnNode(r Record, tableAlias string) (res *Value, err error) {
	// Handle functions that have phrase arguments
	switch e.getFunctionName() {
	case sqlFnCast:
		expr := e.Cast.Expr
		res, err = expr.castTo(r, strings.ToUpper(e.Cast.CastType), tableAlias)

  }

  @Override
  public int bits() {
    return 64;
  }

  @Override
  public String toString() {
    return "Hashing.fingerprint2011()";
  }

  // End of public functions.

  @VisibleForTesting
  static long fingerprint(byte[] bytes, int offset, int length) {
    long result;

    if (length <= 32) {
      result = murmurHash64WithSeed(bytes, offset, length, K0 ^ K1 ^ K2);

  }

  /**
   * A function from an input to a result.
   *
   * @param <T> the type of the input to the function
   * @param <U> the type of the result of the function
   */
  public interface ClosingFunction<T extends @Nullable Object, U extends @Nullable Object> {

    /**
     * Applies this function to an input, or throws an exception if unable to do so.
     *

	Descriptors []MetricDescriptor
	// (Optional) Extra (constant) label KV pairs to be added to each metric in
	// the group.
	ExtraLabels map[string]string

	// Loader functions to load metrics. Only one of these will be set. Metrics
	// returned by these functions must be present in the `Descriptors` list.
	loader       MetricsLoaderFn
	bucketLoader BucketMetricsLoaderFn

	// Cache for all metrics groups. Set via `.SetCache` method.

  fi
}

# This function is designed for maximum compatibility with various platforms. This runs on
# any Mac or Linux platform with bash 4.2+. Please take care not to modify this function
# without testing properly.
#
# This function will properly handle any type of path including those with spaces using the
# loading pattern specified by *kubectl config*.

	if clientConfig.GetGenericXdsConfigs() != nil {
		configs = clientConfig.GetGenericXdsConfigs()
		return configs
	}

	// FIXME: currently removing the deprecated code below may result in functions not working
	// if there is a mismatch of versions between istiod and istioctl
	// nolint: staticcheck
	for _, config := range clientConfig.GetXdsConfig() {
		var typeURL string
		switch config.PerXdsConfig.(type) {

PATH=/bin:/usr/bin:/sbin:/usr/sbin
NAME=fess
DESC="Fess Server"
DEFAULT=/etc/default/$NAME

if [ `id -u` -ne 0 ]; then
	echo "You need root privileges to run this script"
	exit 1
fi


. /lib/lsb/init-functions

if [ -r /etc/default/rcS ]; then
	. /etc/default/rcS
fi

# The following variables can be overwritten in $DEFAULT

# Run Fess as this user ID and group ID
FESS_USER=${packaging.fess.user}