V extends @Nullable Object,
          M extends Multimap<K, V>>
      Collector<T, ?, M> toMultimap(
          java.util.function.Function<? super T, ? extends K> keyFunction,
          java.util.function.Function<? super T, ? extends V> valueFunction,
          java.util.function.Supplier<M> multimapSupplier) {
    return CollectCollectors.<T, K, V, M>toMultimap(keyFunction, valueFunction, multimapSupplier);
  }

  /**

   * {@code function} to the argument, then evaluating using {@code this}. That is, for any pair of
   * non-null objects {@code x} and {@code y}, {@code equivalence.onResultOf(function).equivalent(a,
   * b)} is true if and only if {@code equivalence.equivalent(function.apply(a), function.apply(b))}
   * is true.
   *
   * <p>For example:
   *
   * <pre>{@code

import com.google.common.annotations.GwtCompatible;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A class that can supply objects of a single type; a pre-Java-8 version of {@link
 * java.util.function.Supplier java.util.function.Supplier}. Semantically, this could be a factory,
 * generator, builder, closure, or something else entirely. No guarantees are implied by this
 * interface.
 *

when the function is invoked, not when the "defer" statement is executed.
</p>

<p>
For instance, if the deferred function is
a <a href="#Function_literals">function literal</a> and the surrounding
function has <a href="#Function_types">named result parameters</a> that
are in scope within the literal, the deferred function may access and modify
the result parameters before they are returned.

# Response Model - Return Type

You can declare the type used for the response by annotating the *path operation function* **return type**.

You can use **type annotations** the same way you would for input data in function **parameters**, you can use Pydantic models, lists, dictionaries, scalar values like integers, booleans, etc.

=== "Python 3.10+"

    ```Python hl_lines="16  21"
    {!> ../../../docs_src/response_model/tutorial001_01_py310.py!}
    ```

import java.io.ObjectInputStream;
import java.io.Serializable;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.function.BinaryOperator;
import java.util.function.Function;
import java.util.stream.Collector;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**

		test $foundFiles1 -eq $foundFiles2
		v2=$?
		[ $v1 == 0 -a $v2 == 0 ] && return 0
		sleep 10
	done
	return 1
}

function purge() {
	rm -rf "$1"
}

function __init__() {
	echo "Initializing environment"
	mkdir -p "$WORK_DIR"
	mkdir -p "$MINIO_CONFIG_DIR"

	## version is purposefully set to '3' for minio to migrate configuration file

### Step 4: define the **path operation function**

This is our "**path operation function**":

* **path**: is `/`.
* **operation**: is `get`.
* **function**: is the function below the "decorator" (below `@app.get("/")`).

```Python hl_lines="7"
{!../../../docs_src/first_steps/tutorial001.py!}
```

This is a Python function.

		if ! pkill -9 minio; then
			echo "no minio process running anymore, proceed."
		fi
	fi
}

function check_online() {
	if ! grep -q 'Status:' ${WORK_DIR}/dist-minio-*.log; then
		echo "1"
	fi
}

function purge() {
	rm -rf "$1"
}

function __init__() {
	echo "Initializing environment"
	mkdir -p "$WORK_DIR"
	mkdir -p "$MINIO_CONFIG_DIR"

# Background Tasks - `BackgroundTasks`

You can declare a parameter in a *path operation function* or dependency function with the type `BackgroundTasks`, and then you can use it to schedule the execution of background tasks after the response is sent.

You can import it directly from `fastapi`:

```python
from fastapi import BackgroundTasks
```