invoke() {
    let args = Array.prototype.slice.call(arguments);
    let options = {};

    if (typeof args[args.length - 1] === 'object') {
      options = args.pop();
    }

    return this._invoke(args, options);
  }
The `invoke` method is responsible for building the final executable command.

@private
@method command
@param {String} [...arguments] Arguments to be passed into the command.
@param {Object} [options={}] The options passed into child_process.spawnSync.
  (https://nodejs.org/api/child_process.html#child_process_child_process_spawnsync_command_args_options)