docs: public static String printBase64Binary(byte[] val) {
  
          Assert.notNull(val, "val must not be null!");
  
          String encoded = DatatypeConverter.printBase64Binary(val);
  
          int length = encoded.length();
          StringBuilder sb = new StringBuilder(length + length / RFC2849_MAX_BASE64_CHARS_PER_LINE);
  
          for (int i = 0, len = length; i < len; i++) {
              sb.append(encoded.charAt(i));
  
              if ((i + 1) % RFC2849_MAX_BASE64_CHARS_PER_LINE == 0) {
                  sb.append('\n');
                  sb.append(' ');
              }
          }
  
          return sb.toString();
      }