/** Returns a new {@link Builder}. */
  public static <K, V> Builder<K, V> builder() {
    return new Builder<>();
  }

  /**
   * Returns a new builder with a hint for how many distinct keys are expected to be added. The
   * generated builder is equivalent to that returned by {@link #builder}, but may perform better if
   * {@code expectedKeys} is a good estimate.
   *

	metadata []byte

	// cached contains the metadata if decoded.
	cached *xlMetaV2

	// Indicates the entry can be reused and only one reference to metadata is expected.
	reusable bool
}

// isDir returns if the entry is representing a prefix directory.
func (e metaCacheEntry) isDir() bool {
	return len(e.metadata) == 0 && strings.HasSuffix(e.name, slashSeparator)
}

   *     unrecoverable errors, callers should prefer more specific types, avoiding {@code
   *     Throwable.class} in particular.
   * @param fallback the {@link Function} to be called if {@code input} fails with the expected
   *     exception type. The function's argument is the input's exception. "The input's exception"
   *     means the cause of the {@link ExecutionException} thrown by {@code input.get()} or, if

				// Nothing more for prefix.
				return entries, io.EOF
			}
			partN++
			retries = 0
		}
	}
}

// getListQuorum interprets list quorum values and returns appropriate
// acceptable quorum expected for list operations
func getListQuorum(quorum string, driveCount int) int {
	switch quorum {
	case "disk":
		return 1
	case "reduced":
		return 2
	case "optimal":
		return (driveCount + 1) / 2

	if len(buf) <= 8 {
		return payload, 0, 0, fmt.Errorf("xlMeta: no data")
	}

	if !bytes.Equal(buf[:4], xlHeader[:]) {
		return payload, 0, 0, fmt.Errorf("xlMeta: unknown XLv2 header, expected %v, got %v", xlHeader[:4], buf[:4])
	}

	if bytes.Equal(buf[4:8], []byte("1   ")) {
		// Set as 1,0.
		major, minor = 1, 0
	} else {

  }

  private static void assertErrorMessage(Throwable e, String message) {
    // TODO(kevinb): use a Truth assertion here
    if (!e.getMessage().contains(message)) {
      fail("expected <" + e.getMessage() + "> to contain <" + message + ">");
    }
  }

  /**
   * Test class with valid equals and hashCode methods. Testers created with instances of this class
   * should always pass.
   */

      {
         "datasource": {
            "type": "datasource",
            "uid": "-- Mixed --"
         },
         "description": "Count of active and pending proxies managed by each instance.\nPending is expected to converge to zero.\n",
         "gridPos": {
            "h": 10,
            "w": 8,
            "x": 8,
            "y": 14
         },
         "id": 13,
         "interval": "1m",

        throw thrown;
      }
    }
  }

  private static void assertExecutionException(Future<?> future, Exception expectedCause)
      throws Exception {
    try {
      future.get();
      fail("Expected ExecutionException");
    } catch (ExecutionException e) {
      assertThat(e).hasCauseThat().isSameInstanceAs(expectedCause);
    }
  }

  /** invokeAny(null) throws NPE */

  tensorflow::condition_variable finished_join_;

  // Temporary state between `StartExecute` and `Join`.
  //
  //   Inputs; pointers are to objects not owned by the DeviceThread, but which
  //   are expected to live at least until `Join` finishes:
  TFE_Context* context_ TF_GUARDED_BY(execution_mutex_);
  const char* operation_name_ TF_GUARDED_BY(execution_mutex_);
  absl::optional<int64_t> step_id_ TF_GUARDED_BY(execution_mutex_) =

    @CheckForNull private T value;

    @CheckForNull
    public T get() {
      return value;
    }

    public void checkAndSet(@CheckForNull T expected, @CheckForNull T newValue) {
      if (value != expected) {
        throw new ConcurrentModificationException();
      }
      value = newValue;
    }

    void clear() {
      value = null;
    }
  }