Add unittest of unique_name

* Also follow comments, change prefix to key

python/paddle/v2/fluid/tests/unittests/test_unique_name.py

+#   Copyright (c) 2018 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import unittest
+import paddle.v2.fluid as fluid
+
+
+class TestUniqueName(unittest.TestCase):
+    def test_guard(self):
+        with fluid.unique_name.guard():
+            name_1 = fluid.unique_name.generate('')
+
+        with fluid.unique_name.guard():
+            name_2 = fluid.unique_name.generate('')
+
+        self.assertEqual(name_1, name_2)
+
+        with fluid.unique_name.guard("A"):
+            name_1 = fluid.unique_name.generate('')
+
+        with fluid.unique_name.guard('B'):
+            name_2 = fluid.unique_name.generate('')
+
+        self.assertNotEqual(name_1, name_2)
+
+    def test_generate(self):
+        with fluid.unique_name.guard():
+            name1 = fluid.unique_name.generate('fc')
+            name2 = fluid.unique_name.generate('fc')
+            name3 = fluid.unique_name.generate('tmp')
+            self.assertNotEqual(name1, name2)
+            self.assertEqual(name1[-2:], name3[-2:])

python/paddle/v2/fluid/unique_name.py

@@ -51,8 +51,8 @@ class UniqueNameGenerator(object):
 generator = UniqueNameGenerator()
 
 
-def generate(prefix):
-    return generator(prefix)
+def generate(key):
+    return generator(key)
 
 
 def switch(new_generator=None):