def SEnv_parent_set_test():
p = SEnvironment()
p.define('x', 3)
e = SEnvironment(p)
e.set('x', 5)
eq_(e.lookup('x'), 5)
eq_(p.lookup('x'), 5)
def SEnv_set_undefined_variable_test():
p = SEnvironment()
p.set('x', 3)
def SEnv_set_test():
e = SEnvironment()
e.define('x', 3)
e.set('x', 5)
eq_(e.lookup('x'), 5)
