diff --git a/.obsidian/plugins/obsidian-git/data.json b/.obsidian/plugins/obsidian-git/data.json
index cabac03..1d82f63 100644
--- a/.obsidian/plugins/obsidian-git/data.json
+++ b/.obsidian/plugins/obsidian-git/data.json
@@ -20,7 +20,7 @@
   "mergeStrategy": "none",
   "customMessageOnAutoBackup": false,
   "autoBackupAfterFileChange": false,
-  "treeStructure": true,
+  "treeStructure": false,
   "refreshSourceControl": true,
   "basePath": "",
   "differentIntervalCommitAndPush": false,
diff --git a/.obsidian/workspace-mobile.json b/.obsidian/workspace-mobile.json
index cfb00b8..d60e705 100644
--- a/.obsidian/workspace-mobile.json
+++ b/.obsidian/workspace-mobile.json
@@ -4,33 +4,21 @@
     "type": "split",
     "children": [
       {
-        "id": "567dae9a01eaef2f",
+        "id": "7949e15551785685",
         "type": "tabs",
         "children": [
           {
-            "id": "127ce2a147446e39",
-            "type": "leaf",
-            "state": {
-              "type": "pdf",
-              "state": {
-                "file": "Semester 2/EIST/EIST CHEATSHEET.pdf"
-              },
-              "icon": "lucide-file-text",
-              "title": "EIST CHEATSHEET"
-            }
-          },
-          {
-            "id": "37f018f4ea886da2",
+            "id": "60549d0ba028ec00",
             "type": "leaf",
             "state": {
               "type": "markdown",
               "state": {
-                "file": "EIDI/JVM.md",
+                "file": "Semester 2/EIST/EIST CHEATSHEET.md",
                 "mode": "source",
                 "source": false
               },
               "icon": "lucide-file",
-              "title": "JVM"
+              "title": "EIST CHEATSHEET"
             }
           }
         ]
@@ -163,9 +151,29 @@
           "icon": "lucide-list",
           "title": "Outline"
         }
+      },
+      {
+        "id": "381d17d250860f12",
+        "type": "leaf",
+        "state": {
+          "type": "git-view",
+          "state": {},
+          "icon": "git-pull-request",
+          "title": "Source Control"
+        }
+      },
+      {
+        "id": "39b0dc6fea1c09a5",
+        "type": "leaf",
+        "state": {
+          "type": "git-history-view",
+          "state": {},
+          "icon": "history",
+          "title": "History"
+        }
       }
     ],
-    "currentTab": 0
+    "currentTab": 3
   },
   "left-ribbon": {
     "hiddenItems": {
@@ -181,7 +189,7 @@
       "bases:Create new base": false
     }
   },
-  "active": "127ce2a147446e39",
+  "active": "60549d0ba028ec00",
   "lastOpenFiles": [
     "Semester 2/EIST/EIST CHEATSHEET.md",
     "Semester 2/EIST/EIST CHEATSHEET.pdf",
diff --git a/.obsidian/workspace.json b/.obsidian/workspace.json
index bb0dffe..1e15cb9 100644
--- a/.obsidian/workspace.json
+++ b/.obsidian/workspace.json
@@ -11,14 +11,14 @@
             "id": "3ba46ad009838dd8",
             "type": "leaf",
             "state": {
-              "type": "markdown",
+              "type": "split-diff-view",
               "state": {
-                "file": "Semester 2/EIST/EIST CHEATSHEET.md",
-                "mode": "source",
-                "source": false
+                "aFile": "Semester 2/EIST/EIST CHEATSHEET.md",
+                "bFile": "Semester 2/EIST/EIST CHEATSHEET.md",
+                "aRef": ""
               },
-              "icon": "lucide-file",
-              "title": "EIST CHEATSHEET"
+              "icon": "diff",
+              "title": "Diff: EIST CHEATSHEET  (Working Tree)"
             }
           }
         ]
@@ -174,6 +174,16 @@
               "icon": "git-pull-request",
               "title": "Source Control"
             }
+          },
+          {
+            "id": "96740dab0bf396d5",
+            "type": "leaf",
+            "state": {
+              "type": "git-history-view",
+              "state": {},
+              "icon": "history",
+              "title": "History"
+            }
           }
         ],
         "currentTab": 5
@@ -198,9 +208,9 @@
   },
   "active": "3ba46ad009838dd8",
   "lastOpenFiles": [
+    "Semester 2/EIST/EIST CHEATSHEET.md",
     "Semester 2/EIST/Progress.md",
     "Semester 2/EIST/EIST CHEATSHEET.pdf",
-    "Semester 2/EIST/EIST CHEATSHEET.md",
     "2026-07-10.md",
     "Semester 2/EIST/lu280859klubr.tmp",
     "Semester 2/EIST/lu280859klubn.tmp",
diff --git a/Semester 2/EIST/EIST CHEATSHEET.md b/Semester 2/EIST/EIST CHEATSHEET.md
index c51873c..fdd1b41 100644
--- a/Semester 2/EIST/EIST CHEATSHEET.md	
+++ b/Semester 2/EIST/EIST CHEATSHEET.md	
@@ -580,6 +580,21 @@ public void getAlbumMetadata(EntitiesRequest request, StreamObserver<Albums> res
 	responseObserver.onCompleted();
 }
 ```
+
+#### If you want to return an error
+```java
+public void getTrafficData(RouteRequest request, StreamObserver<TrafficResponse> responseObserver) {
+	var trafficModel = db.getTrafficModel(request);
+	var response = trafficModel.query(request);
+	if(response.isPresent()) {
+		responseObserver.onNext(response.get());
+		responseObserver.onCompleted();
+	} else {
+		// Just pass an exception with the onError method
+		responseObserver.onError(new Exception("No data available."));
+	}
+}
+```
 ## Client Side
 
 #### Setup