*
   * @param sources the sources to concatenate
   * @return a {@code CharSource} containing the concatenated data
   * @since 15.0
   */
  public static CharSource concat(Iterable<? extends CharSource> sources) {
    return new ConcatenatedCharSource(sources);
  }

  /**
   * Concatenates multiple {@link CharSource} instances into a single source. Streams returned from

    CharSource c1 = CharSource.wrap("abc");
    CharSource c2 = CharSource.wrap("");
    CharSource c3 = CharSource.wrap("de");

    String expected = "abcde";

    assertThat(CharSource.concat(ImmutableList.of(c1, c2, c3)).read()).isEqualTo(expected);
    assertThat(CharSource.concat(c1, c2, c3).read()).isEqualTo(expected);

        factory.tearDown();
      }
    };
  }

  private static class StringSourceFactory implements CharSourceFactory {

    @Override
    public CharSource createSource(String data) throws IOException {
      return CharSource.wrap(data);
    }

    @Override
    public String getExpected(String data) {
      return data;
    }

    @Override

public abstract class ByteSource {

  /** Constructor for use by subclasses. */
  protected ByteSource() {}

  /**
   * Returns a {@link CharSource} view of this byte source that decodes bytes read from this source
   * as characters using the given {@link Charset}.
   *
   * <p>If {@link CharSource#asByteSource} is called on the returned source with the same charset,

    }

    /**
     * Returns a {@link CharSource} view of the resource from which its bytes can be read as
     * characters decoded with the given {@code charset}.
     *
     * @throws NoSuchElementException if the resource cannot be loaded through the class loader,
     *     despite physically existing in the class path.
     * @since 20.0
     */
    public final CharSource asCharSource(Charset charset) {

      try (SeekableByteChannel channel = Files.newByteChannel(path, options)) {
        return ByteStreams.toByteArray(Channels.newInputStream(channel), channel.size());
      }
    }

    @Override
    public CharSource asCharSource(Charset charset) {
      if (options.length == 0) {
        // If no OpenOptions were passed, delegate to Files.lines, which could have performance

  /**
   * Returns a {@code ByteSource} that reads base-encoded bytes from the specified {@code
   * CharSource}.
   */
  @J2ktIncompatible
  @GwtIncompatible // ByteSource,CharSource
  public final ByteSource decodingSource(CharSource encodedSource) {
    checkNotNull(encodedSource);
    return new ByteSource() {
      @Override

      return "Files.asByteSink(" + file + ", " + modes + ")";
    }
  }

  /**
   * Returns a new {@link CharSource} for reading character data from the given file using the given
   * character set.
   *
   * @since 14.0
   */
  public static CharSource asCharSource(File file, Charset charset) {
    return asByteSource(file).asCharSource(charset);
  }

  /**

        Writer.class, StringWriter.class,
        PrintStream.class, PrintWriter.class);
    assertEquals(ByteSource.empty(), ArbitraryInstances.get(ByteSource.class));
    assertEquals(CharSource.empty(), ArbitraryInstances.get(CharSource.class));
    assertThat(ArbitraryInstances.get(ByteSink.class)).isNotNull();
    assertThat(ArbitraryInstances.get(CharSink.class)).isNotNull();
  }

  public void testGet_reflect() {

          .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))
          // All collections are immutable empty. So safe for any type parameter.