Example 12

Center allows ConstrainedBox to be any size up to the
screen size. The ConstrainedBox imposes additional
constraints from its constraints parameter onto its child.

The Container must be between 70 and 150 pixels.
It wants to have 100 pixels, and that’s the size it has,
since that’s between 70 and 150.

Example 13

The screen forces the UnconstrainedBox to be exactly
the same size as the screen. However, the UnconstrainedBox
lets its child Container be any size it wants.

Example 14

The screen forces the UnconstrainedBox to be exactly
the same size as the screen, and UnconstrainedBox
lets its child Container be any size it wants.