  from nose.tools import assert_equal
  
  
  class TestCheckBalance(object):
  
 
</s> remove     def test_check_balance(self):
        assert_equal(check_balance(None), False)
 </s> add     @raises(Exception)
    def test_check_balance_empty(self):
        check_balance(None) </s> remove     "* If this is called on a None input, should we return False?\n",
 </s> add     "* If this is called on a None input, should we raise an exception?\n", </s> remove     "* If this is called on a None input, should we return False?\n",
 </s> add     "* If this is called on a None input, should we raise an exception?\n",
from nose.tools import raises
  from nose.tools import assert_equal
from nose.tools import raises
  
  
  class TestCheckBalance(object):
  
add keep keep keep keep
 Polish bst check balanced challenge and solution (#84)

Update constraints, tests, and code. 
graphs_trees/check_balance/test_check_balance.py