code: @NotNull
      public T queryNN() throws SQLException {
          T res = null;
          try (ResultSet r = statement.executeQuery()) {
              if (r.next()) {
                  res = resultMapper.map(r);
              }
              Objects.requireNonNull(res);
              return res;
          }
      }
docs: Same as {@link #query()} but checks if result value is not null.
  Throws {@link java.lang.NullPointerException} if value is null.