Updating rules (#78)

.cursorrules

@@ -128,4 +128,13 @@ Item 86: Implement Serializable with great caution
 Item 87: Consider using a custom serialized form 
 Item 88: Write readObject methods defensively 
 Item 89: For instance control, prefer enum types to readResolve 
-Item 90: Consider serialization proxies instead of serialized instances 
+Item 90: Consider serialization proxies instead of serialized instances 
+
+# Notes to avoid concurency issues
+
+- Try to not maintain state in the class
+
+# Notes to improve functional programming
+
+- Try to use immutable objects
+- Try to not mutate the state of the objects