passThroughOptions(passThrough = true) {
    this._passThroughOptions = !!passThrough;
    this._checkForBrokenPassThrough();
    return this;
  }
Pass through options that come after command-arguments rather than treat them as command-options,
so actual command-options come before command-arguments. Turning this on for a subcommand requires
positional options to have been enabled on the program (parent commands).
The default behaviour is non-positional and options may appear before or after command-arguments.

@param {boolean} [passThrough] for unknown options.
@return {Command} `this` command for chaining