#### Dict { #dict }

To define a `dict`, you pass 2 type parameters, separated by commas.

The first type parameter is for the keys of the `dict`.

The second type parameter is for the values of the `dict`:

{* ../../docs_src/python_types/tutorial008_py310.py hl[1] *}

This means:

* The variable `prices` is a `dict`:

```python
from typing import Optional


def say_hi(name: Optional[str]):
    print(f"Hey {name}!")
```

El parámetro `name` está definido como `Optional[str]`, pero **no es opcional**, no puedes llamar a la función sin el parámetro:

```Python
say_hi()  # ¡Oh, no, esto lanza un error! 😱
```

El parámetro `name` **sigue siendo requerido** (no es *opcional*) porque no tiene un valor por defecto. Aun así, `name` acepta `None` como valor:

```python
from typing import Optional


def say_hi(name: Optional[str]):
    print(f"Hey {name}!")
```

The parameter `name` is defined as `Optional[str]`, but it is **not optional**, you cannot call the function without the parameter:

```Python
say_hi()  # Oh, no, this throws an error! 😱
```

The `name` parameter is **still required** (not *optional*) because it doesn't have a default value. Still, `name` accepts `None` as the value:

import java.util.regex.Pattern;

/**
 * A wrapper class for CrawlerClientFactory that delegates operations to an underlying factory instance.
 * This wrapper allows for parameter management and initialization before delegating to the wrapped factory.
 *
 * The wrapper maintains its own parameter map which can be initialized separately from the wrapped factory,
 * and provides access to the wrapped factory instance through getParent().
 *

import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * A base implementation of {@link NetworkConnections} for directed networks.
 *
 * @author James Sexton
 * @param <N> Node parameter type
 * @param <E> Edge parameter type
 */
abstract class AbstractDirectedNetworkConnections<N, E> implements NetworkConnections<N, E> {
  /** Keys are edges incoming to the origin node, values are the source node. */

 * {@code *} character has no special meaning as part of a parameter. All values for type, subtype,
 * parameter attributes or parameter values must be valid according to RFCs <a
 * href="https://tools.ietf.org/html/rfc2045">2045</a> and <a
 * href="https://tools.ietf.org/html/rfc2046">2046</a>.
 *
 * <p>All portions of the media type that are case-insensitive (type, subtype, parameter attributes)

 */

package com.google.common.cache;

import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.PARAMETER;
import static java.lang.annotation.RetentionPolicy.CLASS;

import com.google.common.annotations.GwtCompatible;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

/**

 */

package com.google.common.graph;

import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.PARAMETER;
import static java.lang.annotation.RetentionPolicy.CLASS;

import com.google.common.annotations.GwtCompatible;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

/**

 */

package com.google.common.hash;

import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.PARAMETER;
import static java.lang.annotation.RetentionPolicy.CLASS;

import com.google.common.annotations.GwtCompatible;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

/**

 */

package com.google.common.net;

import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.PARAMETER;
import static java.lang.annotation.RetentionPolicy.CLASS;

import com.google.common.annotations.GwtCompatible;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

/**