return processedBytes;
          }
        };

    source.read(processor);
    assertTrue(source.wasStreamOpened() && source.wasStreamClosed());

    assertArrayEquals(bytes, processedBytes);
  }

  public void testRead_withProcessor_stopsOnFalse() throws IOException {
    ByteProcessor<@Nullable Void> processor =
        new ByteProcessor<@Nullable Void>() {
          boolean firstCall = true;