This cloning technique requires you to enrich the class with a constructor that takes a single argument representing an instance of the class that will be used to create the clone.

Let's see it in code:

public class Point {

  private double x;
  private double y;

  public Point() {}

  public Point(double x, double y) {
    this.x = x;
    this.y = y;
  }

  public Point(Point another) {
    this.x = another.x;
    this.y = another.y;
  }

  // getters and setters
}

Creating a clone can be done as follows:

Point point = new Point(...);
Point clone = new Point(point);