}

// Comment returns the comment of current column.
func (ct ColumnType) Comment() (value string, ok bool) {
	return ct.CommentValue.String, ct.CommentValue.Valid
}

// DefaultValue returns the default value of current column.
func (ct ColumnType) DefaultValue() (value string, ok bool) {
	return ct.DefaultValueValue.String, ct.DefaultValueValue.Valid

  }

  @Override
  public boolean isPresent() {
    return true;
  }

  @Override
  public T get() {
    return reference;
  }

  @Override
  public T or(T defaultValue) {
    checkNotNull(defaultValue, "use Optional.orNull() instead of Optional.or(null)");
    return reference;
  }

  @Override
  public Optional<T> or(Optional<? extends T> secondChoice) {
    checkNotNull(secondChoice);

   * otherwise, returns {@code defaultValue}.
   *
   * <p>In an undirected graph, this is equal to {@code edgeValueOrDefault(nodeV, nodeU,
   * defaultValue)}.
   *
   * @throws IllegalArgumentException if {@code nodeU} or {@code nodeV} is not an element of this
   *     graph
   */
  @Nullable V edgeValueOrDefault(N nodeU, N nodeV, @Nullable V defaultValue);

  /**

    return false;
  }

  @Override
  public T get() {
    throw new IllegalStateException("Optional.get() cannot be called on an absent value");
  }

  @Override
  public T or(T defaultValue) {
    return checkNotNull(defaultValue, "use Optional.orNull() instead of Optional.or(null)");
  }

  @SuppressWarnings("unchecked") // safe covariant cast
  @Override
  public Optional<T> or(Optional<? extends T> secondChoice) {

          <version>1.1.0+</version>
          <defaultValue>self-first</defaultValue>
          <required>false</required>
          <type>String</type>
        </field>
        <field>
          <name>configuration</name>
          <version>1.2.0+</version>

        // v1 == 0.
        .optional(defaultValue = 0),
      Adapters.INTEGER_AS_BIG_INTEGER,
      algorithmIdentifier,
      name,
      validity,
      name,
      subjectPublicKeyInfo,
      Adapters.BIT_STRING.withTag(tag = 1L).optional(),
      Adapters.BIT_STRING.withTag(tag = 2L).optional(),
      extension.asSequenceOf().withExplicitBox(tag = 3).optional(defaultValue = listOf()),
      decompose = {

     * @param name the property name
     * @param defaultValue the default value to use if property doesn't exist
     * @param appendValue the value to append to the property value
     */
    protected void addSystemProperty(final List<String> cmdList, final String name, final String defaultValue, final String appendValue) {
        final String value = System.getProperty(name);

					alterColumn = true
				}
			case schema.Bool:
				v1, _ := strconv.ParseBool(dv)
				v2, _ := strconv.ParseBool(field.DefaultValue)
				if v1 != v2 {
					alterColumn = true
				}
			case schema.String:
				if dv != field.DefaultValue && dv != strings.Trim(field.DefaultValue, "'\"") {
					alterColumn = true
				}
			default:

          <version>1.0.0</version>
          <name>editable</name>
          <description>Whether the value of this expression can be changed.</description>
          <type>boolean</type>
          <defaultValue>true</defaultValue>
        </field>
      </fields>
    </class>
  </classes>

      }
    };
  }

  private static @Nullable Object getDefaultValue(TypeToken<?> type) {
    Class<?> rawType = type.getRawType();
    Object defaultValue = ArbitraryInstances.get(rawType);
    if (defaultValue != null) {
      return defaultValue;
    }

    // TODO(cpovirk): Support these types in ArbitraryInstances itself?
    if (rawType.equals(Predicate.class)) {