sizeGen :: Gen DisplayRegion
sizeGen = (,)
          <$> (arbitrary `suchThat` (>= 0))
          <*> (arbitrary `suchThat` (>= 0))
sizeGen :: Gen DisplayRegion
sizeGen = (,)
          <$> (arbitrary `suchThat` (>= 0))
          <*> (arbitrary `suchThat` (>= 0))
sizeGen = (,)
          <$> (arbitrary `suchThat` (>= 0))
          <*> (arbitrary `suchThat` (>= 0))