Use test-unit instead of minitest
Minitest 6 will err assert_equal with nil. https://github.com/seattlerb/minitest/issues/779
assert_equal
nil
Added by nobu (Nobuyoshi Nakada) about 6 years ago
Use test-unit instead of minitest
Minitest 6 will err
assert_equalwithnil.https://github.com/seattlerb/minitest/issues/779