adapter refactoring: separated superclass

lib/adapter/adapter.py

@@ -0,0 +1,19 @@
+import abc
+
+class Adapter(object):
+    def __init__(self):
+        self._list = self._get_list()
+
+    @abc.abstractmethod
+    def _get_list(self):
+        return []
+
+    def get_list(self):
+        return self._list
+
+    def is_found(self, topic):
+        return topic in self._list
+
+    @abc.abstractmethod
+    def get_page(self, topic, request_options=None):
+        pass