diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 86b5cf4..38d8e2e 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -24,7 +24,10 @@ jobs:
           --health-interval 10s
           --health-timeout 5s
           --health-retries 5
-          
+        ports:
+          # Maps port 6379 on service container to the host
+          - 6379:6379
+
     steps:
       - uses: actions/checkout@v2
       
diff --git a/src/cst_python/memory_storage/logical_time.py b/src/cst_python/memory_storage/logical_time.py
index 7e84bd9..86e835e 100644
--- a/src/cst_python/memory_storage/logical_time.py
+++ b/src/cst_python/memory_storage/logical_time.py
@@ -3,7 +3,6 @@
 import abc
 import functools
 
-from typing import Self
 
 class LogicalTime(abc.ABC):
 
@@ -23,7 +22,7 @@ def from_str(cls, string:str) -> "LogicalTime":
 
     @classmethod
     @abc.abstractmethod
-    def syncronize(cls, time0:Self, time1:Self) -> "LogicalTime":
+    def syncronize(cls, time0, time1) -> "LogicalTime":
         ...
 
     @abc.abstractmethod
@@ -77,7 +76,7 @@ def from_str(cls, string:str) -> "LamportTime":
         return LamportTime(int(string))
 
     @classmethod
-    def syncronize(cls, time0:Self, time1:Self) -> "LamportTime":
+    def syncronize(cls, time0, time1) -> "LamportTime":
         new_time = 0
         if time0 < time1:
             new_time = time1._time