text: export function stringToBase64Mapper(s) {
      switch (s.length % 4) {
          case 0:
              return s;
          case 3:
              return `${s}=`;
          case 2:
              return `${s}==`;
          default:
              return s.slice(1);
      }
  }
  export function stringToBase64Unmapper(value) {
      if (typeof value !== 'string' || value.length % 4 !== 0) {
          throw new Error('Invalid string received');
      }
      const lastTrailingIndex = value.indexOf('=');
      if (lastTrailingIndex === -1) {
          return value;
      }
      const numTrailings = value.length - lastTrailingIndex;
      if (numTrailings > 2) {
          throw new Error('Cannot unmap the passed value');
      }
      return value.substring(0, lastTrailingIndex);
  }
  