constructor(argv) {
    /** @type {ESDocCLIArgv} */
    this._argv = minimist(argv.slice(2));

    if (this._argv.h || this._argv.help) {
      this._showHelp();
      process.exit(0);
    }

    if (this._argv.v || this._argv.version) {
      this._showVersion();
      process.exit(0);
    }
  }
Create instance.
@param {Object} argv - this is node.js argv(``process.argv``)