[ENH] Change dist_func to four parameters

tests/test_reasoning.py

@@ -101,7 +101,7 @@ class TestReaonser(object):
             excinfo.value
         )
         
-    def random_dist(self, data_sample, candidates, reasoning_results):
+    def random_dist(self, data_sample, candidates, candidate_idxs, reasoning_results):
         cost_list = [np.random.rand() for _ in candidates]
         return cost_list
     
@@ -113,14 +113,14 @@ class TestReaonser(object):
         cost_list = np.array([np.random.rand() for _ in candidates])
         return cost_list
     
-    def invalid_dist2(self, data_sample, candidates, reasoning_results):
+    def invalid_dist2(self, data_sample, candidates, candidate_idxs, reasoning_results):
         cost_list = np.array([np.random.rand() for _ in candidates])
         return np.append(cost_list, np.random.rand())
     
     def test_invalid_user_defined_dist_func(self, kb_add, data_samples_add):
         with pytest.raises(ValueError) as excinfo:
             Reasoner(kb_add, self.invalid_dist1)
-        assert 'User-defined dist_func must have exactly three parameters' in str(
+        assert 'User-defined dist_func must have exactly four parameters' in str(
             excinfo.value
         )
         with pytest.raises(ValueError) as excinfo: