Adds a point to this rectangle. The resulting rectangle is the
smallest rectangle that contains both the original rectangle and the
specified point.
After adding a point, a call to contains with the added
point as an argument does not necessarily return true .
The contains method does not return true
for points on the right or bottom edges of a rectangle. Therefore, if the
added point falls on the left or bottom edge of the enlarged rectangle,
contains returns false for that point.