#495: Add comment in put_to_history

thefuck/shells/generic.py

@@ -83,4 +83,9 @@ class Generic(object):
         return line
 
     def put_to_history(self, command):
-        pass
+        """Adds fixed command to shell history.
+
+        In most of shells we change history on shell-level, but not
+        all shells support it (Fish).
+
+        """