def test_split(self):
w = Wallet()
wp, wn = w.split()
assert w == (wp + wn)
w = Wallet('10 USD')
wp, wn = w.split()
assert w == (wp + wn)
w = Wallet('-10 CAD')
wp, wn = w.split()
assert w == (wp + wn)
w = Wallet(USD='10', CAD='-10')
wp, wn = w.split()
assert w == (wp + wn)
