Bare bones of a notification system

tests/test_trie.py

@@ -0,0 +1,14 @@
+from flake8 import _trie as trie
+
+
+def test_build_tree():
+    tree = trie.Trie()
+    for i in range(5):
+        tree.add('E103', 'E103-listener-{0}'.format(i))
+        j = i + 1
+        tree.add('E1{0}3'.format(j), 'E1{0}3-listener'.format(j))
+    for i in range(10):
+        tree.add('W1{0:02d}'.format(i), 'W1{0:02d}-listener'.format(i))
+
+    assert tree.find('E103') is not None
+    assert tree.find('E200') is None