With the following data Rect::Contains returns false:
*this
{...}
origin:
{...}
x:
472.599945
y:
440.999969
size:
{...}
width:
1102.80005
height:
654.000061
o
0x000000012f8faf30
origin:
{...}
x:
724
y:
618
size:
{...}
width:
600
height:
300
Here is why it fails:
Union(o).size
{...}
width:
1102.80005
height:
654
size
{...}
width:
1102.80005
height:
654.000061