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>1.0.0</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>

      if (isNullable(param)) {
        args.add(null);
        continue;
      }
      Object defaultValue = getDummyValue(param.getType());
      if (defaultValue == null) {
        throw new ParameterNotInstantiableException(param);
      }
      args.add(defaultValue);
    }
    return args;
  }

  private <T> @Nullable T getDummyValue(TypeToken<T> type) {

        FessConfig fessConfig = new FessConfig.SimpleImpl() {
            @Override
            public String getSystemProperty(final String key, final String defaultValue) {
                return systemPropMap.getOrDefault(key, defaultValue);
            }
        };
        ComponentUtil.setFessConfig(fessConfig);
        SystemHelper systemHelper = new SystemHelper() {
            @Override

			case schema.Time:
				if !strings.EqualFold(strings.TrimSuffix(dv, "()"), strings.TrimSuffix(field.DefaultValue, "()")) {
					alterColumn = true
				}
			case schema.Bool:
				v1, _ := strconv.ParseBool(dv)
				v2, _ := strconv.ParseBool(field.DefaultValue)
				alterColumn = v1 != v2
			default:
				alterColumn = dv != field.DefaultValue
			}
		}
	}

	// check comment

         * @param key The property key to look up
         * @param defaultValue The default value to return if the property is not set
         * @return The property value or the default value
         */
        protected String getProperty(final String key, final String defaultValue) {
            return ComponentUtil.getSystemProperties().getProperty(key, defaultValue);
        }

        /**

        return parent.hashCode();
    }

    @Override
    public V getOrDefault(final Object key, final V defaultValue) {
        final V value = parent.get(key);
        if (value != null) {
            return value;
        }
        return parent.getOrDefault(toCamelCase(key), defaultValue);
    }

    @Override
    public void forEach(final BiConsumer<? super K, ? super V> action) {

			},
		},
		ReflectValue: reflect.ValueOf(dest),
		Dest:         dest,
	}

	stmt.Schema = s

	values := ConvertToCreateValues(stmt)
	expected := clause.Values{
		// column has value + defaultValue column has value (which should have a stable order)
		Columns: []clause.Column{{Name: "name"}, {Name: "email"}, {Name: "age"}, {Name: "id"}},
		Values: [][]interface{}{
			{"alice", "email", 18, 1},
			{"bob", "email", 19, 2},

   * determined.
   */
  public static <T> @Nullable T get(Class<T> type) {
    T defaultValue = DEFAULTS.getInstance(type);
    if (defaultValue != null) {
      return defaultValue;
    }
    Class<? extends T> implementation = getImplementation(type);
    if (implementation != null) {
      return get(implementation);
    }

	Length() (length int64, ok bool)
	DecimalSize() (precision int64, scale int64, ok bool)
	Nullable() (nullable bool, ok bool)
	Unique() (unique bool, ok bool)
	ScanType() reflect.Type
	Comment() (value string, ok bool)
	DefaultValue() (value string, ok bool)
}

type Index interface {
	Table() string
	Name() string
	Columns() []string
	PrimaryKey() (isPrimaryKey bool, ok bool)
	Unique() (unique bool, ok bool)
	Option() string
}