code: public static Multimap<String, String> convertToMultiMap(final PObject objectParams) {
          Multimap<String, String> params = HashMultimap.create();
          if (objectParams != null) {
              Iterator<String> customParamsIter = objectParams.keys();
              while (customParamsIter.hasNext()) {
                  String key = customParamsIter.next();
                  if (objectParams.isArray(key)) {
                      final PArray array = objectParams.optArray(key);
                      for (int i = 0; i < array.size(); i++) {
                          params.put(key, array.getString(i));
                      }
                  } else {
                      params.put(key, objectParams.optString(key, ""));
                  }
              }
          }
  
          return params;
      }
docs: convert a param object to a multimap.
  
  @param objectParams the parameters to convert.
  @return the corresponding Multimap.