code: public static boolean isArrayByteBase64(byte[] arrayOctect) {
  
          arrayOctect = discardWhitespace(arrayOctect);
  
          int length = arrayOctect.length;
          if (length == 0) {
              // shouldn't a 0 length array be valid base64 data?
              // return false;
              return true;
          }
          for (int i = 0; i < length; i++) {
              if (!isBase64(arrayOctect[i])) {
                  return false;
              }
          }
          return true;
      }
docs: Tests a given byte array to see if it contains
  only valid characters within the Base64 alphabet.
  
  @param arrayOctect byte array to test
  @return true if all bytes are valid characters in the Base64
  alphabet or if the byte array is empty; false, otherwise