made IsClosed a static function. fixed warnings and errors.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/client/util/UndoManager.ts b/src/client/util/UndoManager.ts
index 536d90371..44e44d335 100644
--- a/src/client/util/UndoManager.ts
+++ b/src/client/util/UndoManager.ts
@@ -106,11 +106,11 @@ export namespace UndoManager {
         return openBatches;
     }
     export function FilterBatches(fieldTypes: string[]) {
-        var fieldCounts: { [key: string]: number } = {};
+        const fieldCounts: { [key: string]: number } = {};
         const lastStack = UndoManager.undoStack.lastElement();
         if (lastStack) {
             lastStack.forEach(ev => fieldTypes.includes(ev.prop) && (fieldCounts[ev.prop] = (fieldCounts[ev.prop] || 0) + 1));
-            var fieldCount2: { [key: string]: number } = {};
+            const fieldCount2: { [key: string]: number } = {};
             runInAction(() =>
                 UndoManager.undoStack[UndoManager.undoStack.length - 1] = lastStack.filter(ev => {
                     if (fieldTypes.includes(ev.prop)) {