@Override
  public int read() throws IOException {
    int read = inputStream.read();
    if (read != -1) fp++;
    return read;
  }
@Test
  public void readExceed() throws IOException {
    byte[] buff = new byte[100];
    int n = cs.read(buff);
    // erase dummy values in the end of buffer
    byte[] buffer = Arrays.copyOfRange(buff, 0, n);

    assertArrayEquals(text, buffer);
    assertEquals(len, n);
  }