fails:StringIO#read when passed length, buffer returns a String in ASCII-8BIT ignoring the encoding of the source String and buffer
fails:StringIO#read when passed length returns a String in ASCII-8BIT encoding when passed a length > 0
fails:StringIO#read when passed length returns an empty String in ASCII-8BIT encoding when passed length == 0
fails:StringIO#read when passed length returns an empty String when passed 0 and no data remains
fails:StringIO#read when passed no arguments returns an empty String in ASCII-8BIT encoding
fails:StringIO#read when passed nil returns an empty String in ASCII-8BIT encoding
