@SuppressWarnings("unchecked") // Assume all default values are generics safe.
    T defaultValue = (T) defaultValues.getInstance(rawType);
    if (defaultValue != null) {
      return defaultValue;
    }
    @SuppressWarnings("unchecked") // ArbitraryInstances always returns generics-safe dummies.
    T value = (T) ArbitraryInstances.get(rawType);
    if (value != null) {
      return value;
    }

    private final String question;
    private final int minValue;
    private final int defaultValue;

    public IntQuestionPromptEvent(long timestamp, String question, int minValue, int defaultValue) {
        super(timestamp);
        this.question = question;
        this.minValue = minValue;
        this.defaultValue = defaultValue;
    }

    public String getQuestion() {
        return question;
    }

    private final String defaultValue;

    public TextQuestionPromptEvent(long timestamp, String question, String defaultValue) {
        super(timestamp);
        this.question = question;
        this.defaultValue = defaultValue;
    }

    public String getQuestion() {
        return question;
    }

    public String getDefaultValue() {
        return defaultValue;
    }

    @Override

    }

    /**
     * オブジェクトを返します。オブジェクトが<code>null</code>だったら<code>defaultValue</code>を返します。
     * <p>
     * 次のように使います．
     * </p>
     *
     * <pre>
     * ObjectUtil.defaultValue(null, "NULL")  = "NULL"
     * ObjectUtil.defaultValue(null, 1)    = 1
     * ObjectUtil.defaultValue(Boolean.TRUE, true) = Boolean.TRUE
     * ObjectUtil.defaultValue(null, null) = null
     * </pre>
     *
     * @param <T>

// and falls back to the given defaultValue if not set
func GetEnvAsStringOrFallback(key, defaultValue string) string {
	if v := os.Getenv(key); v != "" {
		return v
	}
	return defaultValue
}

// GetEnvAsIntOrFallback returns the env variable (parsed as integer) for
// the given key and falls back to the given defaultValue if not set
func GetEnvAsIntOrFallback(key string, defaultValue int) (int, error) {

    private final String systemPropertyName;
    private final boolean defaultValue;

    public InternalFlag(String systemPropertyName) {
        this(systemPropertyName, false);
    }

    public InternalFlag(String systemPropertyName, boolean defaultValue) {
        this.systemPropertyName = systemPropertyName;
        this.defaultValue = defaultValue;
    }

    @Override
    public Boolean getDefaultValue() {

    private String getProperty(String propertyName, String defaultValue) {
        return getProperty(propertyName, defaultValue, true);
    }

    private int getProperty(String propertyName, int defaultValue) {
        return Integer.parseInt(getProperty(propertyName, String.valueOf(defaultValue)));
    }

    private boolean getProperty(String propertyName, boolean defaultValue) {

        return new SystemPropertyRead() {
            @Override
            String getGroovyExpression() {
                return "Integer.getInteger(\"$name\", $defaultValue)"
            }

            @Override
            String getKotlinExpression() {
                return "Integer.getInteger(\"$name\", $defaultValue)"
            }
        }
    }

     * {@link org.codelibs.core.lang.ObjectUtil#defaultValue(Object, Object)} .
     */
    @Test
    public void testDefaultValue() {
        final Hoge hoge = new Hoge();
        assertSame(ObjectUtil.defaultValue(null, hoge), hoge);
        assertSame(ObjectUtil.defaultValue(hoge, null), hoge);
        assertSame(ObjectUtil.defaultValue(hoge, hoge), hoge);
        assertSame(ObjectUtil.defaultValue(null, null), null);

	RegisterVar(v)
	return FloatVar{v}
}

// RegisterDurationVar registers a new duration environment variable.
func RegisterDurationVar(name string, defaultValue time.Duration, description string) DurationVar {
	v := Var{Name: name, DefaultValue: defaultValue.String(), Description: description, Type: DURATION}
	RegisterVar(v)