docs: def value_matrix(self):
          """Converted rows of tabular data.
  
          Returns:
              |list| or |tuple|: Table rows.
          """
  
          if self.__value_matrix:
              return self.__value_matrix
  
          self.__value_matrix = [
              [value_dp.data for value_dp in value_dp_list] for value_dp_list in self.value_dp_matrix
          ]
  
          return self.__value_matrix