fix test overflow error

Author: briangow

wfdb/io/annotation.py

@@ -908,7 +908,12 @@ def create_label_map(self, inplace=True):
         if self.custom_labels is not None:
             self.standardize_custom_labels()
             for i in self.custom_labels.index:
-                label_map.loc[i] = self.custom_labels.loc[i]
+                # label_map.loc[i] = self.custom_labels.loc[i]
+                label_map['label_store'] = label_map['label_store'].astype('int64')
+                cl = self.custom_labels.astype({'label_store': 'int64'}).set_index('label_store')
+                lm = label_map.set_index('label_store').reindex(label_map['label_store'].unique())
+                lm.update(cl[['symbol', 'description']])
+                label_map = lm.reset_index()
 
         if inplace:
             self.__label_map__ = label_map