docs: public String getStringBody() throws UnsupportedEncodingException {
          if (mStringBody != null)
              return mStringBody;
  
          if (mContentType != null) {
              switch (mContentType) {
                  case JSON:
                      JsonObject jsonBody = new JsonObject();
                      for (Map.Entry<String, Object> entry : mBodyMap.entrySet()) {
                          parseHashMapEntry(jsonBody, entry);
                      }
                      mStringBody = jsonBody.toString();
                      break;
                  case URL_ENCODED:
                      HashMap<String, String> stringMap = new HashMap<String, String>();
                      for (Map.Entry<String, Object> entry : mBodyMap.entrySet()) {
                          stringMap.put(entry.getKey(), (String) entry.getValue());
                      }
                      mStringBody = createQuery(stringMap);
                      break;
                  case JSON_PATCH:
                      mStringBody = ((BoxArray) mBodyMap.get(JSON_OBJECT)).toJson();
                      break;
              }
          }
  
          return mStringBody;
      }