namespace tensorflow {

// Abstract interface to an operation.
// This interface allows building and executing an operation in either
// tracing or immediate execution mode.
class AbstractOperation {
 protected:
  enum AbstractOperationKind {
    kGraph,
    kMlir,
    kEager,
    kTfrt,
    kTape,
    kOpHandler
  };
  explicit AbstractOperation(AbstractOperationKind kind) : kind_(kind) {}
  virtual ~AbstractOperation() {}

    ctor.setAccessible(true);
    testParameter(null, Invokable.from(ctor), paramIndex, ctor.getDeclaringClass());
  }

  /** Visibility of any method or constructor. */
  public enum Visibility {
    PACKAGE {
      @Override
      boolean isVisible(int modifiers) {
        return !Modifier.isPrivate(modifiers);
      }
    },

    PROTECTED {
      @Override

    testComparator(ordering, 1, 12, 124, 2);
    assertEquals("Ordering.usingToString()", ordering.toString());
    assertSame(ordering, reserialize(ordering));
  }

  // use an enum to get easy serializability
  private enum CharAtFunction implements Function<String, Character> {
    AT0(0),
    AT1(1),
    AT2(2),
    AT3(3),
    AT4(4),
    AT5(5),
    ;

    final int index;

    testComparator(ordering, 1, 12, 124, 2);
    assertEquals("Ordering.usingToString()", ordering.toString());
    assertSame(ordering, reserialize(ordering));
  }

  // use an enum to get easy serializability
  private enum CharAtFunction implements Function<String, Character> {
    AT0(0),
    AT1(1),
    AT2(2),
    AT3(3),
    AT4(4),
    AT5(5),
    ;

    final int index;

                  }

                  Thread.yield();
                }
              }
            });
  }

  /** Enum defining the two MoreFiles methods that delete directory contents. */
  private enum DirectoryDeleteMethod {
    DELETE_DIRECTORY_CONTENTS {
      @Override
      public void delete(Path path, RecursiveDeleteOption... options) throws IOException {

////

本例中有 3 个查询参数：

* `needy`，必选的 `str` 类型参数
* `skip`，默认值为 `0` 的 `int` 类型参数
* `limit`，可选的 `int` 类型参数

/// tip | "提示"

还可以像在[路径参数](path-params.md#_8){.internal-link target=_blank} 中那样使用 `Enum`。

   *     wait on each method call to the proxy
   * @return a time-limiting proxy
   * @throws IllegalArgumentException if {@code interfaceType} is a regular class, enum, or
   *     annotation type, rather than an interface
   */
  @SuppressWarnings("GoodTime") // should accept a java.time.Duration
  <T> T newProxy(T target, Class<T> interfaceType, long timeoutDuration, TimeUnit timeoutUnit);

         *            The cal to set.
         */
        public void setCal(final Calendar cal) {
            this.cal = cal;
        }
    }

    /**
     *
     */
    public enum MyEnum {
        /**
         *
         */
        ONE,
        /**
         *
         */
        TWO
    }

    /**
     *
     */
    private class MyDto {

 * @author Kevin Bourrillion
 * @since 1.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public final class Booleans {
  private Booleans() {}

  /** Comparators for {@code Boolean} values. */
  private enum BooleanComparator implements Comparator<Boolean> {
    TRUE_FIRST(1, "Booleans.trueFirst()"),
    FALSE_FIRST(-1, "Booleans.falseFirst()");

    private final int trueValue;
    private final String toString;

 * @author Kevin Bourrillion
 * @since 1.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public final class Booleans {
  private Booleans() {}

  /** Comparators for {@code Boolean} values. */
  private enum BooleanComparator implements Comparator<Boolean> {
    TRUE_FIRST(1, "Booleans.trueFirst()"),
    FALSE_FIRST(-1, "Booleans.falseFirst()");

    private final int trueValue;
    private final String toString;