<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def add_data_point_xy(self, x, y):
 """Add a new data point to the data set to be smoothed."""

        self.x.append(x)
        self.y.append(y)