whole_func_string: function makeCigarString(cigarOps: Array<CigarOp>) {
    return cigarOps.map(({op, length}) => length + op).join('');
  }
func_code_string: function makeCigarString(cigarOps: Array<CigarOp>) {
    return cigarOps.map(({op, length}) => length + op).join('');
  }
func_documentation_string: builds a cigarString string that is useful to users.