Match Expand Tests
==================

Match objects have an .expand() method which allows them to
expand templates as if the .sub() method was called on the pattern.

    >>> import re2 as re
    >>> m = re.match(r"(\w+) (\w+)\W+(?P<title>\w+)", "Isaac Newton, physicist")
    >>> m.expand(r"\2, \1")
    'Newton, Isaac'
    >>> m.expand(r"\1 \g<title>")
    'Isaac physicist'
    >>> m.expand(r"\0 \1 \2")
    '\x00 Isaac Newton'
    >>> m.expand(r"\3")
    'physicist'

