invalid-index-returned:36:4:FirstBadIndex.__index__:__index__ does not return int
invalid-index-returned:43:4:SecondBadIndex.__index__:__index__ does not return int
invalid-index-returned:50:4:ThirdBadIndex.__index__:__index__ does not return int
invalid-index-returned:57:4:FourthBadIndex.__index__:__index__ does not return int
