p1 =(0, 0)
Property X changed from 0.0 to 5.0
Property Y changed from 0.0 to 2.0
p1 =(5, 2)
Property X changed from 5.0 to 6.0
Property Y changed from 2.0 to 3.0
p1 =(6, 3)
Property X changed from 6.0 to 12.0
Property Y changed from 3.0 to 7.0
p1 =(12, 7)
Writing to file: (12, 7)
Reading from file: test.tmp
Had: (12, 7)
Got: (12, 7)
