code: def add_extra_datas(self, extra_datas):
          
          # we will add datas starting from the last index
          for index, data in enumerate(extra_datas):
              header = self.extra_headers[index]
              self._datas[-1][header['label']] = data
docs: Add extra datas to the last row
          headers : [col1, col2, col3, col4, col5]
          row : {col1: a1, col2: a2, col3: a3}
          extra_datas : [a4, a5]
  
          row becomes : {col1: a1, col2: a2, col3: a3, col4: a4, col5: a5}
  
          in case of longer extra_datas, the last columns will be overriden
  
          :param list extra_datas: list of values to set in the last columns