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