ion. There
    are two ways of doing this check.

    >>> m = _match(b'/foo', b'', [br're:.*\.c$', b'relpath:a'])

    1. Calling the matcher with a file name returns True if any pattern
    matches that file name:
    >>> m(b'a')
    True
    >>> m(b'main.c')
    True
    >>> m(b'test.py')
    False

    2. Using the exact() method only returns True if the file name matches one
    of the exact patterns (i.e. not re: or glob: patterns):
    >>> m.exact(b'a')
    True
    >>> m.exact(b'main.c')
    False
    c