docs: def value_dp_matrix(self):
          """
          :return: DataProperty for table data.
          :rtype: list
          """
  
          if self.__value_dp_matrix is None:
              self.__value_dp_matrix = self.__dp_extractor.to_dp_matrix(
                  to_value_matrix(self.headers, self.rows)
              )
  
          return self.__value_dp_matrix