fails:IO#each with no separator yields each line to the passed block
fails:IO#each with no separator yields each line starting from the current position
fails:IO#each with no separator returns self
fails:IO#each with no separator does not change $_
fails:IO#each with no separator raises an IOError when self is not readable
fails:IO#each with no separator makes line count accessible via lineno
fails:IO#each with no separator makes line count accessible via $.
fails:IO#each with no separator returns an Enumerator when passed no block
fails:IO#each when passed a String containing one space as a separator uses the passed argument as the line separator
fails:IO#each when passed a String containing one space as a separator does not change $_
fails:IO#each when passed a String containing one space as a separator tries to convert the passed separator to a String using #to_str
fails:IO#each when passed nil as a separator yields self's content starting from the current position when the passed separator is nil
fails:IO#each when passed an empty String as a separator yields each paragraph
fails:IO#each uses $/ as the default line separator
