def test1():
q = Quantity(1, 'km')
assert_eq(q.SI, Quantity(1000, 'm'))
q = Quantity(1, 'm')
assert_eq(q, q.tounit('m'))
q2 = q.copy()
q.inunit('m')
assert_eq(q, q2)
def test_derived_units3():
a = Quantity(2., 'brou', {'brou': Quantity(2., 'bra'),
'bra': Quantity(2., 'bri'),
'bri': Quantity(2., 'bro'),
'bro': Quantity(2, 'bru'),
'bru': Quantity(2., 'stop')})
b = a.tounit('bra')
assert b.magnitude == 4
b = a.tounit('bri')
assert b.magnitude == 8
b = a.tounit('bro')
assert b.magnitude == 16
b = a.tounit('bru')
assert b.magnitude == 32
b = a.tounit('stop')
assert b.magnitude == 64
b = a.SI
assert b.magnitude == 64
assert b.unit == 'stop'