private void _read()
 {
     _buf1 = new MyStr1(5, m_io, this, m_root);
     _buf2 = new MyStr2((2 + 3), true, m_io, this, m_root);
 }
 private void _read()
 {
     _buf1 = new MyStr1(5, m_io, this, m_root);
 }