-- Nil block
nilTests = testGroup "Nil Tests"
  [ testCase "nil is recognized" testNilValid
  , testCase "non-nils are not recognized" testNilInvalid ]
nilTests = testGroup "Nil Tests"
  [ testCase "nil is recognized" testNilValid
  , testCase "non-nils are not recognized" testNilInvalid ]
nilTests = testGroup "Nil Tests"
  [ testCase "nil is recognized" testNilValid
  , testCase "non-nils are not recognized" testNilInvalid ]