Minor fix in Ann class where it didnt had metrics_available in self to retrieve.

modules/module_ann.py

@@ -39,6 +39,8 @@ class Ann:
         self.tree = None
 
         self.tt = TicToc()
+        self.availables_metrics = ['angular','euclidean','manhattan','hamming','dot']
+
 
     def init(self, 
         n_trees: int=10, 
@@ -46,8 +48,7 @@ class Ann:
         n_jobs: int=-1  # n_jobs=-1 Run over all CPU availables
     ) -> None:
 
-        availables_metrics = ['angular','euclidean','manhattan','hamming','dot']
-        assert(metric in self.availables_metrics), f"Error: The value of the parameter 'metric' can only be {availables_metrics}!"
+        assert(metric in self.availables_metrics), f"Error: The value of the parameter 'metric' can only be {self.availables_metrics}!"
 
         print("\tInit tree...")
         self.tt.start()