String name = (String) e.nextElement();
            String value = props.getProperty(name);
            if (value == null) {
                value = callback.apply(name);
            }
            if (name.startsWith(OVERRIDE_PREFIX)) {
                String overrideName = name.substring(OVERRIDE_PREFIX.length());
                props.put(overrideName, substVars(value, name, props, callback));
            } else {

例として次の関数を見てみましょう:

```python
from typing import Optional


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

パラメータ `name` は `Optional[str]` と定義されていますが、任意ではありません。このパラメータなしで関数を呼び出すことはできません:

```Python
say_hi()  # あっ、これはエラーになります！😱
```

`name` パラメータにはデフォルト値がないため、依然として必須（任意ではない）です。ただし、`name` は値として `None` を受け付けます:

```Python
say_hi(name=None)  # これは動作します。None は有効です 🎉
```

    //
    // ----------------------------------------------------------------------

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }

    }

    /**
     * Returns the name of this searcher.
     * The name is derived from the class name by converting it to lowercase
     * and removing the "Searcher" suffix.
     *
     * @return the searcher name
     */
    public String getName() {
        if (name == null) {

     *
     * @param name the pipe name to wait for
     */
    public FsctlPipeWaitRequest(final String name) {
        this.nameBytes = name.getBytes(StandardCharsets.UTF_16LE);
        this.timeoutSpecified = false;
        this.timeout = 0;
    }

    /**
     * Constructs a pipe wait request with timeout.
     *
     * @param name the pipe name to wait for

public class ContainerNotAvailableException extends FessSystemException {

    private static final long serialVersionUID = 1L;

    /** The name of the component that is not available. */
    private String componentName;

    /**
     * Constructor with component name.
     * @param componentName The name of the component that is not available.
     */
    public ContainerNotAvailableException(final String componentName) {

configure<MavenPublishBaseExtension> {
  publishToMavenCentral(automaticRelease = true)
  signAllPublications()
  pom {
    name.set(project.name)
    description.set("Square’s meticulous HTTP client for Java and Kotlin.")
    url.set("https://square.github.io/okhttp/")
    licenses {
      license {
        name.set("The Apache Software License, Version 2.0")
        url.set("https://www.apache.org/licenses/LICENSE-2.0.txt")

-->
<super-source path="super"/>

<inherits name="com.google.common.annotations.Annotations" />
<inherits name="com.google.common.base.Base" />
<inherits name="com.google.common.collect.Collect" />
<inherits name="com.google.gwt.core.Core" />
<inherits name="com.google.gwt.user.User" />
<inherits name="com.google.thirdparty.publicsuffix.PublicSuffixType" />

-->
<super-source path="super"/>

<inherits name="com.google.common.annotations.Annotations" />
<inherits name="com.google.common.base.Base" />
<inherits name="com.google.common.math.Math" />
<inherits name="com.google.common.primitives.Primitives" />
<inherits name="com.google.gwt.core.Core" />
<inherits name="com.google.gwt.user.User" />

{{ $scheme := .Values.tls.enabled | ternary "https" "http" }}
apiVersion: v1
kind: Service
metadata:
  name: {{ template "minio.fullname" . }}
  labels:
    app: {{ template "minio.name" . }}
    chart: {{ template "minio.chart" . }}
    release: {{ .Release.Name }}
    heritage: {{ .Release.Service }}
    monitoring: "true"
  {{- if .Values.service.annotations }}
  annotations: {{- toYaml .Values.service.annotations | nindent 4 }}
  {{- end }}