code: public Map<String, ByteString> rangeQueryRawState(String startKey, String endKey) {
          Map<String, ByteString> map = new HashMap<>();
          for (Chaincode.RangeQueryStateKeyValue mapping : handler.handleRangeQueryState(
                  startKey, endKey, uuid).getKeysAndValuesList()) {
              map.put(mapping.getKey(), mapping.getValue());
          }
          return map;
      }
docs: This method is same as rangeQueryState, except it returns value in ByteString, useful in cases where
  serialized object can be retrieved.
  
  @param startKey
  @param endKey
  @return