  		PreOrder(self.root)
  		return preOrder
  
  	def treeIsEmpty (self):
  		return self.root is None 
</s> remove     "    \n",
 </s> add     "\n", </s> remove    "execution_count": 2,
   "metadata": {
    "collapsed": false
   },
 </s> add    "execution_count": 1,
   "metadata": {}, </s> remove     "        \n",
 </s> add     "\n", </s> remove from nose.tools import assert_equal
 </s> add import unittest
  		PreOrder(self.root)
  		return preOrder
  
  	def treeIsEmpty (self):

keep keep keep keep replace
 #273: Remove nose dependency for staging/ (#283) 
staging/graphs_trees/binary_tree/binary_search_tree.py