setup

test 12,34,56,78 is a rectangle
test not (12,34,56,78 is not a rectangle)

test 123 is not a rectangle
test 1.5 is not a rectangle
test "abc" is not a rectangle

test 0,0,0 is not a rectangle
test 0,0,0,0,0 is not a rectangle

test 0,0,0,"abc" is not a rectangle
test 0,0,0,1.23 is not a rectangle

test empty is not a rectangle

teardown

