FluentIterable<? extends Number> numbers = getSomeNumbers();

    // Sadly, the following is what users will have to do in some circumstances.

    @SuppressWarnings("unchecked") // safe covariant cast
    Optional<Number> first = (Optional<Number>) numbers.first();
    Number value = first.or(0.5); // fine
  }

  @J2ktIncompatible
  @GwtIncompatible // NullPointerTester

        assertTrue(stats.getIntegerOverflowsPrevented() > 0);
    }

    @Test
    public void testBoundaryValues() throws Exception {
        // Test boundary values for safe operations
        assertEquals(Integer.MAX_VALUE, validator.safeAdd(Integer.MAX_VALUE, 0));
        assertEquals(Integer.MIN_VALUE, validator.safeAdd(Integer.MIN_VALUE, 0));

        }
      }
    } finally {
      if (interrupted) {
        Thread.currentThread().interrupt();
      }
    }
    return added;
  }

  /**
   * Returns a synchronized (thread-safe) queue backed by the specified queue. In order to guarantee
   * serial access, it is critical that <b>all</b> access to the backing queue is accomplished
   * through the returned queue.
   *

		xioutil.SafeClose(c.done)
		c.done = nil
	}
	return c.rc.Close()
}

// keepHTTPReqResponseAlive can be used to avoid timeouts with long storage
// operations, such as bitrot verification or data usage scanning.
// Every 10 seconds a space character is sent.
// keepHTTPReqResponseAlive will wait for the returned body to be read before starting the ticker.
// The returned function should always be called to release resources.

    assertEquals(
        "Shouldn't catch any more events when unregistered.", expectedEvents, catcher2.getEvents());
  }

  // NOTE: This test will always pass if register() is thread-safe but may also
  // pass if it isn't, though this is unlikely.
  public void testRegisterThreadSafety() throws Exception {
    List<StringCatcher> catchers = new CopyOnWriteArrayList<>();

 * are stored in the cache until either evicted or manually invalidated. The common way to build
 * instances is using {@link CacheBuilder}.
 *
 * <p>Implementations of this interface are expected to be thread-safe, and can be safely accessed
 * by multiple concurrent threads.
 *
 * <p>When evaluated as a {@link Function}, a cache yields the same result as invoking {@link
 * #getUnchecked}.
 *

    assertEquals(
        "Shouldn't catch any more events when unregistered.", expectedEvents, catcher2.getEvents());
  }

  // NOTE: This test will always pass if register() is thread-safe but may also
  // pass if it isn't, though this is unlikely.
  public void testRegisterThreadSafety() throws Exception {
    List<StringCatcher> catchers = new CopyOnWriteArrayList<>();

        return new SmbFileInputStream(mockFile, mockTree, mockHandle);
    }

    @BeforeEach
    void setUp() throws Exception {
        // Common, safe defaults for collaborators
        when(mockHandle.isValid()).thenReturn(true);
        when(mockHandle.acquire()).thenReturn(mockHandle);
        when(mockHandle.getTree()).thenReturn(mockTree);

    }

    @Test
    public void test_createIndexIfNothing_multipleCallsAreSafe() throws Exception {
        Suggester suggester = createSuggester();

        // Multiple consecutive calls should be safe
        suggester.createIndexIfNothing();
        suggester.createIndexIfNothing();
        suggester.createIndexIfNothing();

        // Should still be able to use the index
        suggester.refresh();

      subgraph.addNode(node);
    }
    for (N node : subgraph.nodes()) {
      for (N successorNode : graph.successors(node)) {
        if (subgraph.nodes().contains(successorNode)) {
          // requireNonNull is safe because the endpoint pair comes from the graph.
          subgraph.putEdgeValue(
              node,
              successorNode,
              requireNonNull(graph.edgeValueOrDefault(node, successorNode, null)));