code: public long[] decode(String hash) {
          if (hash.isEmpty()) {
              return new long[0];
          }
  
          String validChars = this.alphabet + this.guards + this.seps;
          for (int i = 0; i < hash.length(); i++) {
              if (validChars.indexOf(hash.charAt(i)) == -1) {
                  return new long[0];
              }
          }
  
          return this._decode(hash, this.alphabet);
      }
docs: Decrypt string to numbers
  
  @param hash the encrypt string
  @return decryped numbers