} else {
          return TO_BYTE_ARRAY_NEW_STRING.read(byteSource, cs);
        }
      }
    };

    abstract String read(ByteSource byteSource, Charset cs) throws IOException;
  }

  @Param({"UTF-8"})
  String charsetName;

  @Param ReadStrategy strategy;

  @Param({"10", "1024", "1048576"})
  int size;

  Charset charset;
  ByteSource data;

  @BeforeExperiment
  public void setUp() {

    joinHelper(1, 1, 1, 1, 1, 1, 1, 1);
    joinHelper(1, 0, 1, 0, 1, 0, 1, 0);
  }

  public void testOnlyOneOpen() throws Exception {
    ByteSource source = newByteSource(0, 50);
    int[] counter = new int[1];
    ByteSource checker =
        new ByteSource() {
          @Override
          public InputStream openStream() throws IOException {
            if (counter[0]++ != 0) {

  private final TestByteSource byteSource;

  public TestCharSource(String content, TestOption... options) {
    this.byteSource = new TestByteSource(content.getBytes(UTF_8), options);
  }

  @Override
  public boolean wasStreamOpened() {
    return byteSource.wasStreamOpened();
  }

  @Override
  public boolean wasStreamClosed() {
    return byteSource.wasStreamClosed();
  }

  @Override

    ByteSource source = out.asByteSource();
    int chunk1 = min(dataSize, fileThreshold);
    int chunk2 = dataSize - chunk1;

    // Write just enough to not trip the threshold
    if (chunk1 > 0) {
      write(out, data, 0, chunk1, singleByte);
      assertTrue(ByteSource.wrap(data).slice(0, chunk1).contentEquals(source));
    }
    File file = out.getFile();

    joinHelper(1, 1, 1, 1, 1, 1, 1, 1);
    joinHelper(1, 0, 1, 0, 1, 0, 1, 0);
  }

  public void testOnlyOneOpen() throws Exception {
    ByteSource source = newByteSource(0, 50);
    int[] counter = new int[1];
    ByteSource checker =
        new ByteSource() {
          @Override
          public InputStream openStream() throws IOException {
            if (counter[0]++ != 0) {

 * the License.
 */

/**
 * Utility methods and classes for I/O; for example input streams, output streams, readers, writers,
 * and files.
 *
 * <p>At the core of this package are the Source/Sink types: {@link ByteSource ByteSource}, {@link
 * CharSource CharSource}, {@link ByteSink ByteSink} and {@link CharSink CharSink}. They are
 * factories for I/O streams that provide many convenience methods that handle both opening and
 * closing streams for you.

  private Resources() {}

  /**
   * Returns a {@link ByteSource} that reads from the given URL.
   *
   * @since 14.0
   */
  public static ByteSource asByteSource(URL url) {
    return new UrlByteSource(url);
  }

  /** A byte source that reads from a URL using {@link URL#openStream()}. */
  private static final class UrlByteSource extends ByteSource {

    private final URL url;

    ByteSource source = out.asByteSource();
    int chunk1 = min(dataSize, fileThreshold);
    int chunk2 = dataSize - chunk1;

    // Write just enough to not trip the threshold
    if (chunk1 > 0) {
      write(out, data, 0, chunk1, singleByte);
      assertTrue(ByteSource.wrap(data).slice(0, chunk1).contentEquals(source));
    }
    File file = out.getFile();

@GwtIncompatible
final class MultiInputStream extends InputStream {

  private final Iterator<? extends ByteSource> it;
  private @Nullable InputStream in;

  /**
   * Creates a new instance.
   *
   * @param it an iterator of I/O suppliers that will provide each substream
   */
  public MultiInputStream(Iterator<? extends ByteSource> it) throws IOException {
    this.it = checkNotNull(it);
    advance();
  }

  @Override

import org.jspecify.annotations.NullUnmarked;

/**
 * A byte source for testing that has configurable behavior.
 *
 * @author Colin Decker
 */
@NullUnmarked
public final class TestByteSource extends ByteSource implements TestStreamSupplier {

  private final byte[] bytes;
  private final ImmutableSet<TestOption> options;

  private boolean inputStreamOpened;
  private boolean inputStreamClosed;