@Override
  public int read() {
    if (nextChar == UNSET || nextChar >= buf.length) {
      fill();
      if (nextChar == UNSET) {
        return END_OF_STREAM;
      }
    }
    byte signedByte = buf[nextChar];
    nextChar++;
    return signedByte & 0xFF;
  }
@Test
  void read_from_ClosableIterator_with_single_line() throws IOException {
    assertThat(read(create("line1"))).isEqualTo("line1");
  }