core: remove obsolte groupfilter code

--HG--
extra : convert_revision : svn%3Ab85faa78-f9eb-468e-a121-7cced6da292c%40847

scrapy/trunk/scrapy/core/scheduler/__init__.py

@@ -1,3 +1,2 @@
 from scrapy.core.scheduler.schedulers import Scheduler
-from scrapy.core.scheduler.filter import GroupFilter
 from scrapy.core.scheduler.store import MemoryStore

scrapy/trunk/scrapy/core/scheduler/filter.py

@@ -1,19 +0,0 @@
-class GroupFilter(dict):
-    """Filter groups of keys"""
-    def open(self, group):
-        self[group] = set()
-
-    def close(self, group):
-        del self[group]
-
-    def add(self, group, key):
-        """Add a key to the group if an equivalent key has not already been added.
-        This method will return true if the key was added and false otherwise.
-        """
-        if key not in self[group]:
-            self[group].add(key)
-            return True
-        return False
-
-    def has(self, group, key):
-        return key in self[group]

scrapy/trunk/scrapy/tests/test_groupfilter.py

@@ -1,27 +0,0 @@
-import unittest
-from scrapy.core.scheduler import GroupFilter
-
-class GroupFilterTest(unittest.TestCase):
-
-    def test_groupfilter(self):
-        k1 = "id1"
-        k2 = "id1"
-
-        f = GroupFilter()
-        f.open("mygroup")
-        self.assertTrue(f.add("mygroup", k1))
-        self.assertFalse(f.add("mygroup", k1))
-        self.assertFalse(f.add("mygroup", k2))
-
-        f.open('anothergroup')
-        self.assertTrue(f.add("anothergroup", k1))
-        self.assertFalse(f.add("anothergroup", k1))
-        self.assertFalse(f.add("anothergroup", k2))
-
-        f.close('mygroup')
-        f.open('mygroup')
-        self.assertTrue(f.add("mygroup", k2))
-        self.assertFalse(f.add("mygroup", k1))
-
-if __name__ == "__main__":
-    unittest.main()