'Make sure each whitespace lookbehind takes into account the effect
of previous replacements\' whitespace additions.
When this bug existed, strip_fors would add a
for postspace to the
2nd {/for}, but then the preceding_whitespace call for the next {for}
wouldn\'t see what was added, since it was still looking in the
original string, without the replacements applied.'

def test_matches_see_replacements(self):

    strip_eq('\x070\x07\n\n\x071\x07Fx4\x07/sf\x07\n\n\x07/sf\x07\n\n\x072\x07\n\n\x073\x07Fx3\x07/sf\x07\n\n\x07/sf\x07', '{for    fx4}\n{for    mac}Fx4{/for}\n{/for}\n{for    fx3}\n{for    mac}Fx3{/for}\n{/for}')
