DataInput in = new LittleEndianDataInputStream(new ByteArrayInputStream(data));
    UnsupportedOperationException expected =
        assertThrows(UnsupportedOperationException.class, () -> in.readLine());
    assertThat(expected).hasMessageThat().isEqualTo("readLine is not supported");
  }

  public void testReadLittleEndian() throws IOException {
    DataInput in = new LittleEndianDataInputStream(new ByteArrayInputStream(data));

  @CanIgnoreReturnValue // to skip a line
  @Override
  @DoNotCall("Always throws UnsupportedOperationException")
  public String readLine() {
    throw new UnsupportedOperationException("readLine is not supported");
  }

  @Override
  public void readFully(byte[] b) throws IOException {
    ByteStreams.readFully(this, b);
  }

  @Override

    } else {
      assertEquals(expectedLines.get(0), source.readFirstLine());
    }
  }

  public void testReadLines_toList() throws IOException {
    assertExpectedLines(source.readLines());
  }

  public void testIsEmpty() throws IOException {
    assertEquals(expected.isEmpty(), source.isEmpty());
  }

  public void testLength() throws IOException {

  }

  public void testReadLines() throws IOException {
    // TODO(chrisn): Check in a better resource
    URL resource = getClass().getResource("testdata/i18n.txt");
    assertEquals(ImmutableList.of(I18N), Resources.readLines(resource, Charsets.UTF_8));
  }

  public void testReadLines_withLineProcessor() throws IOException {
    URL resource = getClass().getResource("testdata/alice_in_wonderland.txt");

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.io.IOException;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A callback to be used with the streaming {@code readLines} methods.
 *
 * <p>{@link #processLine} will be called for each line that is read, and should return {@code
 * false} when you want to stop processing.
 *
 * @author Miles Barr
 * @since 1.0
 */
@J2ktIncompatible

import java.util.ArrayDeque;
import java.util.Queue;
import javax.annotation.CheckForNull;

/**
 * A class for reading lines of text. Provides the same functionality as {@link
 * java.io.BufferedReader#readLine()} but for all {@link Readable} objects, not just instances of
 * {@link Reader}.
 *
 * @author Chris Nokleberg
 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault

  @Override
  float readFloat();

  @CanIgnoreReturnValue // to skip some bytes
  @Override
  double readDouble();

  @CanIgnoreReturnValue // to skip a line
  @Override
  @CheckForNull
  String readLine();

  @CanIgnoreReturnValue // to skip a field
  @Override
  String readUTF();

    assertEquals(ImmutableList.of("foo", "bar", "baz", "something"), lines.readLines());
    assertTrue(lines.wasStreamOpened() && lines.wasStreamClosed());
  }

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