fails:StringIO#initialize when passed keyword arguments accepts a mode argument set to nil with a valid :mode option
fails:StringIO#initialize when passed keyword arguments accepts a mode argument with a :mode option set to nil
fails:StringIO#initialize when passed keyword arguments sets binmode from :binmode option
fails:StringIO#initialize when passed keyword arguments does not set binmode from false :binmode
fails:StringIO#initialize when passed keyword arguments sets the mode based on the passed :mode option
