/**
 * Legacy version of {@link java.util.function.Function java.util.function.Function}.
 *
 * <p>The {@link Functions} class provides common functions and related utilities.
 *
 * <p>As this interface extends {@code java.util.function.Function}, an instance of this type can be
 * used as a {@code java.util.function.Function} directly. To use a {@code
 * java.util.function.Function} in a context where a {@code com.google.common.base.Function} is

   * typically by writing {@code (Function<Object, String> & Serializable) Object::toString}.
   *
   * <p>For more important information about the transition from Guava's {@link Function} class to
   * the JDK {@link java.util.function.Function} class, see {@link Function}.
   */
  public static Function<Object, String> toStringFunction() {
    return ToStringFunction.INSTANCE;
  }

    Function<? super Integer, Boolean> h = Functions.constant(Boolean.TRUE);
    Function<? super String, Integer> g = new HashCodeFunction();
    Function<Float, String> f = Functions.forMap(m, "F");

    Function<Float, Boolean> c1 = Functions.compose(Functions.compose(h, g), f);
    Function<Float, Boolean> c2 = Functions.compose(h, Functions.compose(g, f));

{* ../../docs_src/background_tasks/tutorial001.py hl[1,13] *}

**FastAPI** will create the object of type `BackgroundTasks` for you and pass it as that parameter.

## Create a task function { #create-a-task-function }

Create a function to be run as the background task.

It is just a standard function that can receive parameters.

efineProperty(t,o.key,o)}}function y(t,e){return(y=Object.setPrototypeOf||function(t,e){return t.__proto__=e,t})(t,e)}function h(n){var o=function(){if("undefined"==typeof Reflect||!Reflect.construct)return!1;if(Reflect.construct.sham)return!1;if("function"==typeof Proxy)return!0;try{return Date.prototype.toString.call(Reflect.construct(Date,[],function(){})),!0}catch(t){return!1}}();return function(){var t,e=v(n);return t=o?(t=v(this).constructor,Reflect.construct(e,arguments,t)):e.apply(this,a...

    <function-class>org.codelibs.fess.taglib.FessFunctions</function-class>
    <function-signature>java.lang.String mltForm()</function-signature>
    <example>
      ${fe:mltForm()}
    </example>
  </function>

  <function>
    <description>
      Returns a hidden form for Geo.
    </description>
    <name>geoForm</name>
    <function-class>org.codelibs.fess.taglib.FessFunctions</function-class>

  }

  /**
   * 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
   */
  @FunctionalInterface
  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.
     *

 *  @author Victor Jonsson, http://victorjonsson.se
 *  @license MIT
 */

      searchForm: $("#searchForm")
    });
  }

  loadImage = function(img, url, limit) {
    var imgData = new Image();
    $(imgData).on("load", function() {
      $(img).css("background-image", "");
      $(img).attr("src", url);
    });
    $(imgData).on("error", function() {
      if (limit > 0) {
        setTimeout(function() {
          loadImage(img, url, --limit);
        }, IMG_LOADING_DELAY);

    /**
     * Creates a composite function from a collection of functions.
     *
     * @param functions A collection of functions, each taking a String as input and returning a String.
     * @return A function that applies each function in the collection in order until a non-null result is found.
     *         If all functions return null, the composite function returns null.
     *