def __add__(self, entry):
number_points = self.number_points + entry.number_points;<EOL>result_linear_sum = list_math_addition(self.linear_sum, entry.linear_sum);<EOL>result_square_sum = self.square_sum + entry.square_sum;  <EOL>return cfentry(number_points, result_linear_sum, result_square_sum)<EOL>
!
        @brief Overloaded operator add. Performs addition of two clustering features.

        @param[in] entry (cfentry): Entry that is added to the current.

        @return (cfentry) Result of addition of two clustering features.