def _normalize(c):
if isinstance(c, int):<EOL><INDENT>return bytes([c])<EOL><DEDENT>elif isinstance(c, str):<EOL><INDENT>return bytes([ord(c)])<EOL><DEDENT>else:<EOL><INDENT>return c<EOL><DEDENT>
Convert a byte-like value into a canonical byte (a value of type 'bytes' of len 1)

:param c:
:return: