* false} when you want to stop processing.
 *
 * @author Miles Barr
 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public interface LineProcessor<T extends @Nullable Object> {

  /**
   * This method will be called once for each line.
   *
   * @param line the line read from the input, without delimiter
   * @return true to continue processing, false to stop

  }

  public void testReadLines_withLineProcessor() throws IOException {
    URL resource = getClass().getResource("testdata/alice_in_wonderland.txt");
    LineProcessor<List<String>> collectAndLowercaseAndTrim =
        new LineProcessor<List<String>>() {
          List<String> collector = new ArrayList<>();

          @Override
          public boolean processLine(String line) {

  }

  public void testReadLines_withLineProcessor() throws IOException {
    String text = "a\nb\nc";

    // Test a LineProcessor that always returns false.
    Reader r = new StringReader(text);
    LineProcessor<Integer> alwaysFalse =
        new LineProcessor<Integer>() {
          int seen;

          @Override
          public boolean processLine(String line) {
            seen++;

  }

  public void testReadLines_withLineProcessor() throws IOException {
    String text = "a\nb\nc";

    // Test a LineProcessor that always returns false.
    Reader r = new StringReader(text);
    LineProcessor<Integer> alwaysFalse =
        new LineProcessor<Integer>() {
          int seen;

          @Override
          public boolean processLine(String line) {
            seen++;

   * @param callback the LineProcessor to use to handle the lines
   * @return the output of processing the lines
   * @throws IOException if an I/O error occurs
   */
  @CanIgnoreReturnValue // some processors won't return a useful result
  @ParametricNullness
  public static <T extends @Nullable Object> T readLines(
      URL url, Charset charset, LineProcessor<T> callback) throws IOException {

    }
  }

  public void testReadLines_withProcessor() throws IOException {
    List<String> list =
        source.readLines(
            new LineProcessor<List<String>>() {
              List<String> list = Lists.newArrayList();

              @Override
              public boolean processLine(String line) throws IOException {
                list.add(line);

    assertTrue(temp.delete());
  }

  public void testReadLines_withLineProcessor() throws IOException {
    File temp = createTempFile();
    LineProcessor<List<String>> collect =
        new LineProcessor<List<String>>() {
          List<String> collector = new ArrayList<>();

          @Override
          public boolean processLine(String line) {
            collector.add(line);

  }

  public void testReadLines_withProcessor() throws IOException {
    TestCharSource lines = new TestCharSource(LINES);
    List<String> list =
        lines.readLines(
            new LineProcessor<List<String>>() {
              List<String> list = Lists.newArrayList();

              @Override
              public boolean processLine(String line) throws IOException {
                list.add(line);

    }
  }

  public void testReadLines_withProcessor() throws IOException {
    List<String> list =
        source.readLines(
            new LineProcessor<List<String>>() {
              List<String> list = Lists.newArrayList();

              @Override
              public boolean processLine(String line) throws IOException {
                list.add(line);

  }

  public void testReadLines_withLineProcessor() throws IOException {
    URL resource = getClass().getResource("testdata/alice_in_wonderland.txt");
    LineProcessor<List<String>> collectAndLowercaseAndTrim =
        new LineProcessor<List<String>>() {
          List<String> collector = new ArrayList<>();

          @Override
          public boolean processLine(String line) {