{!../../docs_src/python_types/tutorial009c.py!}
```

De parameter `name` is gedefinieerd als `Optional[str]`, maar is **niet optioneel**, je kunt de functie niet aanroepen zonder de parameter:

```Python
say_hi()  # Oh, nee, dit geeft een foutmelding! 😱
```

De `name` parameter is **nog steeds vereist** (niet *optioneel*) omdat het geen standaardwaarde heeft. Toch accepteert `name` `None` als waarde:

```Python

                                    <label for="name" class="col-sm-3 text-sm-right col-form-label"><la:message
                                            key="labels.labeltype_name"/></label>
                                    <div class="col-sm-9">
                                        <la:errors property="name"/>
                                        <la:text styleId="name" property="name" styleClass="form-control"/>

            script {
                name = "CALCULATE_MD5_VERSION_FOR_DOGFOODING_DISTRIBUTION"
                workingDir = "%teamcity.build.checkoutDir%/dogfood-first-for-hash"
                scriptContent = """
                    set -x
                    MD5=`find . -type f | sort | xargs md5sum | md5sum | awk '{ print $1 }'`

	pod, ns := buildFakePodAndNSForClient()

	proxy := corev1.Container{Name: "istio-proxy"}
	app := corev1.Container{Name: "app"}

	pod.Spec.Containers = []corev1.Container{app, proxy}
	pod.ObjectMeta.Annotations = map[string]string{annotation.SidecarStatus.Name: "true"}
	ns.ObjectMeta.Labels = map[string]string{label.IoIstioDataplaneMode.Name: constants.DataplaneModeAmbient}

	testDoAddRun(t, cniConf, testNSName, pod, ns)

                            {
                                "title": "Full Name",
                                "anyOf": [{"type": "string"}, {"type": "null"}],
                            }
                        )
                        | IsDict(
                            # TODO: remove when deprecating Pydantic v1
                            {"title": "Full Name", "type": "string"}
                        ),
                    },

                require(project.description != null) { "You must set the description of published project ${project.name}" }
                project.description
            }
            url = "https://gradle.org"
            licenses {
                license {
                    name = "Apache-2.0"
                    url = "http://www.apache.org/licenses/LICENSE-2.0.txt"
                }
            }

    PropertyDoc(ClassMetaData referringClass, PropertyMetaData propertyMetaData, List<Element> comment, List<ExtraAttributeDoc> additionalValues) {
        name = propertyMetaData.name
        this.referringClass = referringClass
        this.metaData = propertyMetaData
        id = "${referringClass.className}:$name"
        this.comment = comment
        if (additionalValues == null) {

    ],
)

cc_library(
    name = "abstract_op_attrs",
    hdrs = ["abstract_op_attrs.h"],
    visibility = [
        "//tensorflow:internal",
    ],
    deps = [
        "//tensorflow/core:lib",
        "//tensorflow/core:protos_all_cc",
        "@com_google_absl//absl/container:inlined_vector",
    ],
)

cc_library(
    name = "abstract_operation",
    hdrs = ["abstract_operation.h"],

import org.dbflute.optional.OptionalThing;

public abstract class RankFusionSearcher {
    protected String name;

    public String getName() {
        if (name == null) {
            name = StringUtil.decamelize(this.getClass().getSimpleName().replace("Searcher", StringUtil.EMPTY)).toLowerCase(Locale.ENGLISH);
        }
        return name;
    }

    <relativePath></relativePath>
  </parent>

  <name>Guava BOM</name>
  <description>BOM for Guava artifacts</description>
  <url>https://github.com/google/guava</url>
  <inceptionYear>2010</inceptionYear>

  <issueManagement>
    <system>GitHub Issues</system>
    <url>https://github.com/google/guava/issues</url>
  </issueManagement>

  <licenses>
    <license>
      <name>Apache License, Version 2.0</name>