/**
   * Invoked as soon as a call is enqueued or executed by a client. In case of thread or stream
   * limits, this call may be executed well before processing the request is able to begin.
   *
   * This will be invoked only once for a single [Call]. Retries of different routes or redirects
   * will be handled within the boundaries of a single [callStart] and [callEnd]/[callFailed] pair.
   */
  open fun callStart(call: Call) {
  }

  /**

	opts     promhttp.HandlerOpts
	auth     func(http.Handler) http.Handler

	metricsData *metricsV3Collection
}

var (
	globalMetricsV3CollectorPaths []collectorPath
	globalMetricsV3Once           sync.Once
)

func newMetricsV3Server(auth func(h http.Handler) http.Handler) *metricsV3Server {
	registry := prometheus.NewRegistry()
	metricGroups := newMetricGroups(registry)
	globalMetricsV3Once.Do(func() {

// GetObjectReader is a type that wraps a reader with a lock to
// provide a ReadCloser interface that unlocks on Close()
type GetObjectReader struct {
	io.Reader
	ObjInfo    ObjectInfo
	cleanUpFns []func()
	once       sync.Once
}

// WithCleanupFuncs sets additional cleanup functions to be called when closing
// the GetObjectReader.
func (g *GetObjectReader) WithCleanupFuncs(fns ...func()) *GetObjectReader {

        when(cfg.getBufferCacheSize()).thenReturn(2);
        when(cfg.getMaximumBufferSize()).thenReturn(5);

        BufferCacheImpl impl = new BufferCacheImpl(cfg);

        // Verify interactions happen exactly once during construction
        verify(cfg, times(1)).getBufferCacheSize();
        verify(cfg, times(1)).getMaximumBufferSize();
        verifyNoMoreInteractions(cfg);

        assertEquals("keep1/", it.next().getName());
        assertTrue(it.hasNext());
        assertEquals("keep2/", it.next().getName());
        assertFalse(it.hasNext());

        // Verify filter called once per entry
        verify(filter, times(3)).accept(any());
    }

    @Test
    @DisplayName("Filter throws CIFSException: entry is skipped and iteration continues")

  /** True if there are more exchanges expected for this call. */
  private var expectMoreExchanges = true

  // These properties are accessed by canceling threads. Any thread can cancel a call, and once it's
  // canceled it's canceled forever.

  @Volatile private var canceled = false

  @Volatile private var exchange: Exchange? = null
  internal val plansToCancel = CopyOnWriteArrayList<RoutePlanner.Plan>()

   * returns a {@link SortedSet}, instead of the {@link java.util.Collection} specified in the
   * {@link Multimap} interface.
   *
   * <p>Any duplicates in {@code values} will be stored in the multimap once.
   */
  @CanIgnoreReturnValue
  @Override
  SortedSet<V> replaceValues(@ParametricNullness K key, Iterable<? extends V> values);

  /**

h3. Discovery all Plexus components

Once the ClassRealm is populated with the plugin artifact and its dependency artifacts a discovery operation must be performed on the plugin ClassRealm in order to discover any Plexus components that may be present in any of the artifacts required for the plugins execution.

h3. Looking up the plugin with a configuration

 * It implements the {@link DocumentReader} interface to provide a way to iterate over documents
 * in a large index without loading all of them into memory at once.
 * </p>
 *
 * <p>
 * The reader supports limiting the number of documents read based on a percentage of the total documents

  // Features

  private final Set<Feature<?>> features = new LinkedHashSet<>();

  /**
   * Configures this builder to produce tests appropriate for the given features. This method may be
   * called more than once to add features in multiple groups.
   */
  @CanIgnoreReturnValue
  public B withFeatures(Feature<?>... features) {
    return withFeatures(asList(features));
  }

  @CanIgnoreReturnValue