assertExpectedLines(source.readLines());
  }

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

  public void testLength() throws IOException {
    assertEquals(expected.length(), source.length());
  }

  public void testLengthIfKnown() throws IOException {
    Optional<Long> lengthIfKnown = source.lengthIfKnown();

    }

    abstract void doIt(ImmutableLongArray.Builder builder, AtomicLong counter);
  }

  private static final Random random = new Random(42);

  public void testLength() {
    assertThat(ImmutableLongArray.of().length()).isEqualTo(0);
    assertThat(ImmutableLongArray.of(0).length()).isEqualTo(1);
    assertThat(ImmutableLongArray.of(0, 1, 3).length()).isEqualTo(3);

    }

    abstract void doIt(ImmutableDoubleArray.Builder builder, AtomicInteger counter);
  }

  private static final Random random = new Random(42);

  public void testLength() {
    assertThat(ImmutableDoubleArray.of().length()).isEqualTo(0);
    assertThat(ImmutableDoubleArray.of(0).length()).isEqualTo(1);
    assertThat(ImmutableDoubleArray.of(0, 1, 3).length()).isEqualTo(3);

    }

    abstract void doIt(ImmutableLongArray.Builder builder, AtomicLong counter);
  }

  private static final Random random = new Random(42);

  public void testLength() {
    assertThat(ImmutableLongArray.of().length()).isEqualTo(0);
    assertThat(ImmutableLongArray.of(0).length()).isEqualTo(1);
    assertThat(ImmutableLongArray.of(0, 1, 3).length()).isEqualTo(3);

        int sizeNeeded = destIndex + charsSkipped + escaped.length;
        if (dest.length < sizeNeeded) {
          int destLength = sizeNeeded + (end - index) + DEST_PAD;
          dest = growBuffer(dest, destIndex, destLength);
        }
        // If we have skipped any characters, we need to copy them now.
        if (charsSkipped > 0) {