* be an empty line at the end if the contents are terminated with a line separator.
 *
 * <p>Any {@link ByteSource} containing text encoded with a specific {@linkplain Charset character
 * encoding} may be viewed as a {@code CharSource} using {@link ByteSource#asCharSource(Charset)}.
 *
 * <p><b>Note:</b> In general, {@code CharSource} is intended to be used for "file-like" sources

    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

    suite.addTestSuite(FilesTest.class);
    return suite;
  }

  public void testRoundTripSources() throws Exception {
    File asciiFile = getTestFile("ascii.txt");
    ByteSource byteSource = Files.asByteSource(asciiFile);
    assertSame(byteSource, byteSource.asCharSource(UTF_8).asByteSource(UTF_8));
  }

  public void testToByteArray() throws IOException {
    File asciiFile = getTestFile("ascii.txt");

          .put(FloatBuffer.class, FloatBuffer.allocate(0))
          .put(DoubleBuffer.class, DoubleBuffer.allocate(0))
          .put(File.class, new File(""))
          .put(ByteSource.class, ByteSource.empty())
          .put(CharSource.class, CharSource.empty())
          .put(ByteSink.class, NullByteSink.INSTANCE)
          .put(CharSink.class, NullByteSink.INSTANCE.asCharSink(UTF_8))

    assertFreshInstanceReturned(
        ByteArrayOutputStream.class, OutputStream.class,
        Writer.class, StringWriter.class,
        PrintStream.class, PrintWriter.class);
    assertEquals(ByteSource.empty(), ArbitraryInstances.get(ByteSource.class));
    assertEquals(CharSource.empty(), ArbitraryInstances.get(CharSource.class));
    assertNotNull(ArbitraryInstances.get(ByteSink.class));
    assertNotNull(ArbitraryInstances.get(CharSink.class));

          .put(FloatBuffer.class, FloatBuffer.allocate(0))
          .put(DoubleBuffer.class, DoubleBuffer.allocate(0))
          .put(File.class, new File(""))
          .put(ByteSource.class, ByteSource.empty())
          .put(CharSource.class, CharSource.empty())
          .put(ByteSink.class, NullByteSink.INSTANCE)
          .put(CharSink.class, NullByteSink.INSTANCE.asCharSink(UTF_8))

    suite.addTestSuite(FilesTest.class);
    return suite;
  }

  public void testRoundTripSources() throws Exception {
    File asciiFile = getTestFile("ascii.txt");
    ByteSource byteSource = Files.asByteSource(asciiFile);
    assertSame(byteSource, byteSource.asCharSource(UTF_8).asByteSource(UTF_8));
  }

  public void testToByteArray() throws IOException {
    File asciiFile = getTestFile("ascii.txt");

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;

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;