[Documentation] Didn't save a part of the topological sorting docstring!

Author: exterkamp

structures/graph.py

@@ -46,7 +46,8 @@ def topological_sort(self):
 
         The algorithm looks at every node, and does a
         dfs for each node adjacent to the node and then adds
-        the originating node to a stack.  In the end, the stack
+        the originating node to a stack once all adjacent
+        nodes have been searched.  In the end, the stack
         will be in order of a possible topological sort.
 
         Topological sorts are not necessarily unique.