fails:IO#initialize uses the external encoding specified in the mode argument
fails:IO#initialize uses the external and the internal encoding specified in the mode argument
fails:IO#initialize uses the external encoding specified via the :external_encoding option
fails:IO#initialize uses the internal encoding specified via the :internal_encoding option
fails:IO#initialize uses the colon-separated encodings specified via the :encoding option
fails:IO#initialize ingores the :encoding option when the :external_encoding option is present
fails:IO#initialize ingores the :encoding option when the :internal_encoding option is present
fails:IO#initialize uses the encoding specified via the :mode option hash
fails:IO#initialize ignores the :internal_encoding option when the same as the external encoding
