text: class StringBuilder {
    constructor(value) {
      this._value = value;
    }
  
    get value() {
      return this._value;
    }
  
    append(str) {
      this._value = this._value + str;
    }
  
    prepend(str) {
      this._value = str + this._value;
    }
  
    pad(str) {
      this._value = str + this._value + str;
    }
  }
  
  const builder = new StringBuilder('.');
  
  builder.append('^');
  console.log(builder.value); // '.^'
  
  builder.prepend('^');
  console.log(builder.value); // '^.^'
  
  builder.pad('=');
  console.log(builder.value); // '=^.^='
  
  