Fill an entry of the observation table.
        Args:
            row (str): The row of the observation table
            col (str): The column of the observation table
        Returns:
            None

def _fill_table_entry(self, row, col):
        """""
        Fill an entry of the observation table.
        Args:
            row (str): The row of the observation table
            col (str): The column of the observation table
        Returns:
            None
        """
        prefix = self._membership_query(row)
        full_output = self._membership_query(row + col)
        length = len(commonprefix([prefix, full_output]))
        self.observation_table[row, col] = full_output[length:]