policyCondStartsWith    = "starts-with"
	policyCondContentLength = "content-length-range"
)

// toString - Safely convert interface to string without causing panic.
func toString(val interface{}) string {
	switch v := val.(type) {
	case string:
		return v
	default:
		return ""
	}
}

// toLowerString - safely convert interface to lower string
func toLowerString(val interface{}) string {
	return strings.ToLower(toString(val))

@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
abstract class CollectionFuture<V extends @Nullable Object, C extends @Nullable Object>
    extends AggregateFuture<V, C> {
  /*
   * We access this field racily but safely. For discussion of a similar situation, see the comments
   * on the fields of TimeoutFuture. This field is slightly different from the fields discussed

~~ TODO document META-INF/maven/slf4j-configuration.properties

* Getting Logger Instance

 Starting with Maven 3.1.0, SLF4J Logger can be used directly. This technique can be used safely in Maven core
 components or in plugins/component not requiring compatibility with previous Maven versions.

+-----+
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class MyClass
{

   * write.
   *
   * 2. visibility of the writes to an afterDone() call triggered by cancel():
   *
   * Since these fields are non-final that means that TimeoutFuture is not being 'safely published',
   * thus a motivated caller may be able to expose the reference to another thread that would then
   * call cancel() and be unable to cancel the delegate.

    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();

    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();

    }

    /**
     * @return True if the <code>Mojo</code> is thread-safe and can be run safely in parallel
     * @since 3.0-beta-2
     */
    public boolean isThreadSafe() {
        return threadSafe;
    }

    /**
     * @param threadSafe indicates that the mojo is thread-safe and can be run safely in parallel
     * @since 3.0-beta-2
     */
    public void setThreadSafe(boolean threadSafe) {

        toArrayCalled = true;
        return super.toArray(a);
      }
    }

    // Test that toArray() is used to make a defensive copy in copyOf(), so concurrently modified
    // synchronized collections can be safely copied.
    TestArrayList<String> toCopy = new TestArrayList<>();
    ImmutableSortedMultiset<String> unused =
        ImmutableSortedMultiset.copyOf(Ordering.natural(), toCopy);
    assertTrue(toCopy.toArrayCalled);
  }

        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) {

    }
    return false;
  }

  /**
   * Returns a "Java hash code" for this {@code HashCode} instance; this is well-defined (so, for
   * example, you can safely put {@code HashCode} instances into a {@code HashSet}) but is otherwise
   * probably not what you want to use.
   */
  @Override
  public final int hashCode() {