put' = test $ do
    B.writeFile "myhist" $ invalidHist
    assertInvocation (setUTF8 i) input output'

utf8TestValidHist ::
  Invocation -> [BC.ByteString] -> [BC.ByteString] -> Test
utf8TestValidHist i input outpu
utf8TestInvalidHist ::
  Invocation -> [BC.ByteString] -> [BC.ByteString] -> Test
utf8TestInvalidHist i input output' = test $ do
    B.writeFile "myhist" $ invalidHist
    assertInvocation (setUTF8 i) input output'
utf8TestInvalidHist i input output' = test $ do
    B.writeFile "myhist" $ invalidHist
    assertInvocation (setUTF8 i) input output'