return charsToSkip;
  }

  @Override
  public synchronized boolean ready() throws IOException {
    checkOpen();
    return true;
  }

  @Override
  public boolean markSupported() {
    return true;
  }

  @Override
  public synchronized void mark(int readAheadLimit) throws IOException {
    checkArgument(readAheadLimit >= 0, "readAheadLimit (%s) may not be negative", readAheadLimit);

  }

  public void testMarkAndReset() throws IOException {
    String string = "abcdefghijklmnopqrstuvwxyz";
    CharSequenceReader reader = new CharSequenceReader(string);
    assertTrue(reader.markSupported());

    assertEquals(string, readFully(reader));
    assertFullyRead(reader);

    // reset and read again
    reader.reset();
    assertEquals(string, readFully(reader));
    assertFullyRead(reader);

      if (result != -1) {
        left -= result;
      }
      return result;
    }

    @Override
    public synchronized void reset() throws IOException {
      if (!in.markSupported()) {
        throw new IOException("Mark not supported");
      }
      if (mark == -1) {
        throw new IOException("Mark not set");
      }

      in.reset();
      left = mark;
    }

    server.enqueue(builder.build())
    server.enqueue(builder.build())
    val inputStream = getResponse(newRequest("/")).body.byteStream()
    assertThat(inputStream.markSupported(), "This implementation claims to support mark().")
      .isFalse()
    inputStream.mark(5)
    assertThat(readAscii(inputStream, 5)).isEqualTo("ABCDE")
    assertFailsWith<IOException> {