diff --git a/abl/abducer/kb.py b/abl/abducer/kb.py
index fb606f3..8bb7854 100644
--- a/abl/abducer/kb.py
+++ b/abl/abducer/kb.py
@@ -26,6 +26,10 @@ import pyswip
 
 class KBBase(ABC):
     def __init__(self, pseudo_label_list, len_list=None, GKB_flag=False, max_err=0):
+        # TODO：添加一下类型检查，比如
+        # if not isinstance(X, (np.ndarray, spmatrix)):
+        #     raise TypeError("X should be numpy array or sparse matrix")
+
         self.pseudo_label_list = pseudo_label_list
         self.len_list = len_list
         self.GKB_flag = GKB_flag
@@ -161,6 +165,7 @@ class KBBase(ABC):
             new_candidates += candidates
         return new_candidates
 
+    # TODO：在类初始化时应该有一个cache（默认True）的参数，用户可以指定是否用cache（若KB会变，那不能用cache）
     @lru_cache(maxsize=100)
     def _abduce_by_search(self, pred_res, key, max_address_num, require_more_address, multiple_predictions):
         pred_res = hashable_to_list(pred_res)