count++;
                if (count > 10)
                    break; // Safety check
            }
            assertEquals(0, count, "No iterations should occur for empty iterator");
        }, "EmptyIterator should work with manual iteration");
    }

    @Test
    @DisplayName("EmptyIterator should handle concurrent access safely")
    void testConcurrentAccess() throws InterruptedException, CIFSException {

    fakePool.runAll();
    assertEquals(2, totalCalls.get());
    // Queue is empty so no runner should be scheduled.
    assertFalse(fakePool.hasNext());

    // Check that execute can be safely repeated
    e.execute(intCounter);
    e.execute(intCounter);
    e.execute(intCounter);
    // No change yet.
    assertEquals(2, totalCalls.get());
    fakePool.runAll();

            }
          };

      @Override
      public void validateClass(Class<? extends Exception> exceptionClass) {
        isValidClass.get(exceptionClass); // throws if invalid; returns safely (and caches) if valid
      }
    }

    enum WeakSetValidator implements GetCheckedTypeValidator {
      INSTANCE;

      /*

 * 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}.
 *

        throw new IllegalArgumentException(
            "missing event subscriber for an annotated method. Is " + listener + " registered?");
      }

      // don't try to remove the set if it's empty; that can't be done safely without a lock
      // anyway, if the set is empty it'll just be wrapping an array of length 0
    }
  }

  @VisibleForTesting
  Set<Subscriber> getSubscribersForTesting(Class<?> eventType) {

            // Then
            assertEquals(4, bytesRead);
        }

        @Test
        @DisplayName("Should handle concurrent access safely")
        void testConcurrentAccess() throws InterruptedException {
            // Given
            int threadCount = 10;
            Thread[] threads = new Thread[threadCount];

			// that we promised that we would write.
			if totalSize > 0 && written != totalSize {
				return written, io.ErrUnexpectedEOF
			}
			return written, nil
		}
	}
}

// SafeClose safely closes any channel of any type
func SafeClose[T any](c chan<- T) {
	if c != nil {
		close(c)
		return
	}
	// Print stack to check who is sending `c` as `nil`
	// without crashing the server.

 * 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.
 *
 * @param <K> the type of the cache's keys, which are not permitted to be null
 * @param <V> the type of the cache's values, which are not permitted to be null

	if c != nil {
		c2 := c.clone()
		c = &c2
	}
	p.cycleInfoMu.Lock()
	p.cycleInfo = c
	p.cycleInfoMu.Unlock()
}

// getCycle returns the current cycle metrics.
// If not nil, the returned value can safely be modified.
func (p *scannerMetrics) getCycle() *currentScannerCycle {
	p.cycleInfoMu.Lock()
	defer p.cycleInfoMu.Unlock()
	if p.cycleInfo == nil {
		return nil
	}
	c := p.cycleInfo.clone()
	return &c

	if !ok {
		return ""
	}
	return pCfg.ClaimPrefix + pCfg.ClaimName
}

// LookupUser lookup userid for the provider
func (r Config) LookupUser(roleArn, userid string) (provider.User, error) {
	// Can safely ignore error here as empty or invalid ARNs will not be
	// mapped.
	arnVal, _ := arn.Parse(roleArn)
	pCfg, ok := r.arnProviderCfgsMap[arnVal]
	if ok {
		user, err := pCfg.provider.LookupUser(userid)