text: class VariablePool {
      /**
       * @param {string} prefix The prefix at the start of the variable name.
       */
      constructor (prefix) {
          if (prefix.trim().length === 0) {
              throw new Error('prefix cannot be empty');
          }
          this.prefix = prefix;
          /**
           * @private
           */
          this.count = 0;
      }
  
      next () {
          return `${this.prefix}${this.count++}`;
      }
  }
  
  module.exports = VariablePool;
  