assertThat(Doubles.join(",", EMPTY)).isEmpty();
    assertThat(Doubles.join(",", ARRAY1)).isEqualTo("1.0");
    assertThat(Doubles.join(",", 1.0, 2.0)).isEqualTo("1.0,2.0");
    assertThat(Doubles.join("", 1.0, 2.0, 3.0)).isEqualTo("1.02.03.0");
  }

  public void testJoinNonTrivialDoubles() {
    assertThat(Doubles.join(",", EMPTY)).isEmpty();
    assertThat(Doubles.join(",", 1.2)).isEqualTo("1.2");

            // Non-critical failures - should NOT open circuit
            for (int i = 0; i < 5; i++) {
                try {
                    customCb.executeWithCircuitBreaker(() -> {
                        throw new RuntimeException("non-critical error");
                    }, isFailure);
                    fail("Should have thrown exception");

   *
   * <ul>
   *   <li>All non-private static methods are checked such that passing null for any parameter
   *       that's not annotated nullable should throw {@link NullPointerException}.
   *   <li>If there is any non-private constructor or non-private static factory method declared by
   *       {@code cls}, all non-private instance methods will be checked too using the instance

                response.writeBytesWireFormat(buffer2, 0);
            });

            thread1.start();
            thread2.start();
            thread1.join();
            thread2.join();

            // Then - no exceptions should occur
            assertTrue(true);
        }
    }

                results[index] = thumbnailGenerator.generate(thumbnailId, outputFile);
            });
            threads[i].start();
        }

        for (Thread thread : threads) {
            thread.join();
        }

        for (boolean result : results) {
            assertTrue(result);
        }
    }

    /**
     * Test implementation of ThumbnailGenerator interface
     */

    waiter1.interrupt();

    waiter1.join();
    waiter2.awaitWaiting(); // should still be blocked

    LockSupport.unpark(waiter2); // spurious wakeup
    waiter2.awaitWaiting(); // should eventually re-park

    future.set(null);
    waiter2.join();
  }

  public void testRemoveWaiter_polling() throws Exception {

    assertThat(Doubles.join(",", EMPTY)).isEmpty();
    assertThat(Doubles.join(",", ARRAY1)).isEqualTo("1.0");
    assertThat(Doubles.join(",", 1.0, 2.0)).isEqualTo("1.0,2.0");
    assertThat(Doubles.join("", 1.0, 2.0, 3.0)).isEqualTo("1.02.03.0");
  }

  public void testJoinNonTrivialDoubles() {
    assertThat(Doubles.join(",", EMPTY)).isEmpty();
    assertThat(Doubles.join(",", 1.2)).isEqualTo("1.2");

import org.jspecify.annotations.Nullable;

/**
 * To be implemented by test generators of things that can contain elements. Such things include
 * both {@link Collection} and {@link Map}; since there isn't an established collective noun that
 * encompasses both of these, 'container' is used.
 *
 * @author George van den Driessche
 */
@GwtCompatible
@NullMarked
public interface TestContainerGenerator<T, E extends @Nullable Object> {

                            // so put an additional one
                            buffer.push("");
                        }
                        const bufferValue = buffer.join("<br>");
                        dataValue["value"] = bufferValue;
                        useLines.push(dataValue);
                        buffer = [];
                    }
                }

            });
            readThreads[i].start();
        }

        // Wait for all threads
        for (Thread thread : updateThreads) {
            thread.join(5000);
        }
        for (Thread thread : readThreads) {
            thread.join(5000);
        }

        // Verify final state
        assertEquals(100, entry.getChildren().size());
        assertTrue(entry.hasChanges());
    }