fails:Integer#chr without argument infers the encoding from Encoding.default_internal
fails:Integer#chr with an encoding argument returns a String
fails:Integer#chr with an encoding argument returns a new String for each call
fails:Integer#chr with an encoding argument accepts an Encoding object as an argument
fails:Integer#chr with an encoding argument returns characters in the specified encoding even if they exist in US-ASCII
fails:Integer#chr with an encoding argument behaves as called with no argument if encoding is specified as US-ASCII and self is less than 128
fails:Integer#chr with an encoding argument behaves as called with no argument if encoding is specified as ASCII-8BIT and self is between 128 and 255
fails:Integer#chr with an encoding argument interprets self as a codepoint in the corresponding character set
fails:Integer#chr with an encoding argument raises a RangeError if self is an invalid codepoint for the given encoding
fails:Integer#chr with an encoding argument raises a RangeError is self is less than 0
