fails:Encoding::Converter#convpath returns an Array
fails:Encoding::Converter#convpath returns each encoding pair as a sub-Array
fails:Encoding::Converter#convpath returns each encoding as an Encoding object
fails:Encoding::Converter#convpath returns multiple encoding pairs when direct conversion is impossible
fails:Encoding::Converter#convpath sets the last element of each pair to the first element of the next
fails:Encoding::Converter#convpath only lists a source encoding once
fails:Encoding::Converter#convpath indicates if crlf_newline conversion would occur
