code: @Deprecated
      public static String encodePostBody(Bundle parameters, String boundary) {
          if (parameters == null) return "";
          StringBuilder sb = new StringBuilder();
  
          for (String key : parameters.keySet()) {
              Object parameter = parameters.get(key);
              if (!(parameter instanceof String)) {
                  continue;
              }
  
              sb.append("Content-Disposition: form-data; name=\"" + key +
                      "\"\r\n\r\n" + (String)parameter);
              sb.append("\r\n" + "--" + boundary + "\r\n");
          }
  
          return sb.toString();
      }
docs: Generate the multi-part post body providing the parameters and boundary
  string
  
  @param parameters the parameters need to be posted
  @param boundary the random string as boundary
  @return a string of the post body