From 40bd01fdffd88d935dee90e87fef607ef6764fb2 Mon Sep 17 00:00:00 2001
From: "vn.py" <xiaoyou.chen@foxmail.com>
Date: Thu, 13 Jun 2019 20:15:19 +0800
Subject: [PATCH] Revert "[Add] metaclass of singleton"

This reverts commit b05eb7142e60fd3cb93e6b04e1c7e89746670462.
---
 vnpy/trader/utility.py | 14 --------------
 1 file changed, 14 deletions(-)

diff --git a/vnpy/trader/utility.py b/vnpy/trader/utility.py
index fc4ab4cd..a154e175 100644
--- a/vnpy/trader/utility.py
+++ b/vnpy/trader/utility.py
@@ -445,17 +445,3 @@ def virtual(func: "callable"):
     that can be (re)implemented by subclasses.
     """
     return func
-
-
-class Singleton(type):
-    """
-    Metaclass for creating singleton object.
-    """
-    _instances = {}
-
-    def __call__(cls, *args, **kwargs):
-        """"""
-        if cls not in cls._instances:
-            cls._instances[cls] = super(
-                Singleton, cls).__call__(*args, **kwargs)
-        return cls._instances[cls]