refresh() {
    if (!this.parent || !this._activePrompt) {
      return this;
    }
    this._activePrompt.screen.clean();
    this._activePrompt.render();
    this._activePrompt.rl.output.write(this._activePrompt.rl.line);
    return this;
  }
Redraws the inquirer prompt with a new string.

@param {String} str
@return {UI}
@api private