code: function () {
              var state = this.state,
                  currentPage = state.pages[state.currentPage - 1],
                  rowIndex = currentPage.rowIndex,
                  nextRow = state.rows[rowIndex + 1];
              return nextRow && nextRow[0] + 1 || state.currentPage;
          }
docs: Calculates the next page
  @returns {int} The next page number