diff --git a/samples/react-graph-cascading-managed-metadata/fast-serve/config.json b/samples/react-graph-cascading-managed-metadata/fast-serve/config.json
index fbb6384ca..45fdbf596 100644
--- a/samples/react-graph-cascading-managed-metadata/fast-serve/config.json
+++ b/samples/react-graph-cascading-managed-metadata/fast-serve/config.json
@@ -2,5 +2,8 @@
   "$schema": "https://raw.githubusercontent.com/s-KaiNet/spfx-fast-serve/master/schema/config.latest.schema.json",
   "cli": {
     "isLibraryComponent": false
+  },
+  "serve": {
+    "open": false
   }
 }
\ No newline at end of file
diff --git a/samples/react-graph-cascading-managed-metadata/src/webparts/cascadingManagedMetadata/CascadingManagedMetadataWebPart.ts b/samples/react-graph-cascading-managed-metadata/src/webparts/cascadingManagedMetadata/CascadingManagedMetadataWebPart.ts
index 005a2a5ff..ed873be14 100644
--- a/samples/react-graph-cascading-managed-metadata/src/webparts/cascadingManagedMetadata/CascadingManagedMetadataWebPart.ts
+++ b/samples/react-graph-cascading-managed-metadata/src/webparts/cascadingManagedMetadata/CascadingManagedMetadataWebPart.ts
@@ -16,8 +16,12 @@ export default class CascadingManagedMetadataWebPart extends BaseClientSideWebPa
 
   private _placeholder = null;
 
-  public async render(): Promise<void> {
+  protected async onInit(): Promise<void> {
     await MSGraph.Init(this.context);
+    return super.onInit();
+  }
+
+  public async render(): Promise<void> {
     let renderElement = null;
     if (this.properties.termSetId) {
       renderElement = React.createElement(
diff --git a/samples/react-graph-cascading-managed-metadata/src/webparts/cascadingManagedMetadata/components/CascadingManagedMetadata.tsx b/samples/react-graph-cascading-managed-metadata/src/webparts/cascadingManagedMetadata/components/CascadingManagedMetadata.tsx
index 3b06c522f..fafc633fb 100644
--- a/samples/react-graph-cascading-managed-metadata/src/webparts/cascadingManagedMetadata/components/CascadingManagedMetadata.tsx
+++ b/samples/react-graph-cascading-managed-metadata/src/webparts/cascadingManagedMetadata/components/CascadingManagedMetadata.tsx
@@ -29,7 +29,7 @@ const CascadingManagedMetadata: React.SFC<ICascadingManagedMetadataProps> = (pro
   //* Check if the term set has a property called UsedForShowingMaps
   const _checkIfTermsetIsUsedForShowingMaps = async (): Promise<boolean> => {
     try {
-      const termsetData = await MSGraph.Get(`/termStore/sets/${props.termSetId}`, "beta", ["properties"]);
+      const termsetData = await MSGraph.Call('get', `/termStore/sets/${props.termSetId}`, "beta", {}, ["properties"]);
       const termsetProperties: IProperty[] = termsetData.properties;
       console.debug("%s Retrieved termset properties. %o", LOG_SOURCE, termsetProperties);
 
@@ -53,7 +53,7 @@ const CascadingManagedMetadata: React.SFC<ICascadingManagedMetadataProps> = (pro
   //* Get the country terms i.e. level 1 children using Graph
   const _getCountries = async (): Promise<ITerms> => {
     try {
-      let countries: ITerms = await MSGraph.Get(`/termStore/sets/${props.termSetId}/children`, "beta");
+      let countries: ITerms = await MSGraph.Call('get', `/termStore/sets/${props.termSetId}/children`, "beta");
       setMessageBarStatus(state => ({ ...state, show: false }));
       console.debug("%s Retrieved countries. %o", LOG_SOURCE, countries);
       return countries;
diff --git a/samples/react-graph-cascading-managed-metadata/src/webparts/cascadingManagedMetadata/services/MMDService.ts b/samples/react-graph-cascading-managed-metadata/src/webparts/cascadingManagedMetadata/services/MMDService.ts
index 78c559619..23ff89785 100644
--- a/samples/react-graph-cascading-managed-metadata/src/webparts/cascadingManagedMetadata/services/MMDService.ts
+++ b/samples/react-graph-cascading-managed-metadata/src/webparts/cascadingManagedMetadata/services/MMDService.ts
@@ -25,7 +25,7 @@ export class MMDService {
 
     private static async _getTermsAsDropdownOptionsUsingGraph(apiUrl: string, selectProperties: string[], parent: string): Promise<ICMMDDropdownOption[]> {
         try {
-            let terms: ITerms = await MSGraph.Get(apiUrl, "beta", selectProperties);
+            let terms: ITerms = await MSGraph.Call("get", apiUrl, "beta", {}, selectProperties);
             if (terms.value) {
                 const options: ICMMDDropdownOption[] = terms.value.map(t => ({
                     key: t.id,
diff --git a/samples/react-graph-cascading-managed-metadata/src/webparts/cascadingManagedMetadata/services/MSGraph.ts b/samples/react-graph-cascading-managed-metadata/src/webparts/cascadingManagedMetadata/services/MSGraph.ts
index ab4be1bf6..4f005477f 100644
--- a/samples/react-graph-cascading-managed-metadata/src/webparts/cascadingManagedMetadata/services/MSGraph.ts
+++ b/samples/react-graph-cascading-managed-metadata/src/webparts/cascadingManagedMetadata/services/MSGraph.ts
@@ -1,3 +1,5 @@
+//* Helper wrapper for calling Graph
+//* based on https://gist.github.com/wobba/37416d3107b85675d896105554b3df28
 //* Thank you Mikael Svenson
 
 import { WebPartContext } from '@microsoft/sp-webpart-base';
@@ -6,88 +8,33 @@ import { MSGraphClient } from '@microsoft/sp-http';
 
 export class MSGraph {
     private static _graphClient: MSGraphClient;
+
     public static async Init(context: WebPartContext) {
         this._graphClient = await context.msGraphClientFactory.getClient();
     }
 
-    public static async Get(apiUrl: string, version: string = "v1.0", selectProperties?: string[], expandProperties?: string[], filter?: string, count?: boolean): Promise<any> {
+    public static async Call(
+        method: "get" | "post" | "patch" | "delete",
+        apiUrl: string,
+        version: "v1.0" | "beta",
+        content?: any,
+        selectProperties?: string[],
+        expandProperties?: string[],
+        filter?: string,
+        count?: boolean
+    ): Promise<any> {
+        
         var p = new Promise<string>(async (resolve, reject) => {
             let query = this._graphClient.api(apiUrl).version(version);
-            if (selectProperties && selectProperties.length > 0) {
-                query = query.select(selectProperties);
-            }
-            if (filter && filter.length > 0) {
-                query = query.filter(filter);
-            }
-            if (expandProperties && expandProperties.length > 0) {
-                query = query.expand(expandProperties);
-            }
-            if (count) {
-                query = query.count(true);
-            }
-
-            let callback = (error: GraphError, response: any, rawResponse?: any) => {
-                if (error) {
-                    reject(error);
-                } else {
-                    resolve(response);
-                }
-            };
-            await query.get(callback);
+            typeof(content) === "object" && (content = JSON.stringify(content));
+            selectProperties && selectProperties.length > 0 && (query = query.select(selectProperties));
+            filter && filter.length > 0 && (query = query.filter(filter));
+            expandProperties && expandProperties.length > 0 && (query = query.expand(expandProperties));
+            count && (query = query.count(count));
+            let callback = (error: GraphError, response: any, rawResponse?: any) => error ? reject(error) : resolve(response);
+            //* ES2016
+            ["post", "patch"].includes(method) ? await query[method](content, callback) : await query[method](callback);
         });
         return p;
     }
-
-    public static async Patch(apiUrl: string, version: string = "v1.0", content: any): Promise<any> {
-        var p = new Promise<string>(async (resolve, reject) => {
-            if (typeof (content) === "object") {
-                content = JSON.stringify(content);
-            }
-
-            let query = this._graphClient.api(apiUrl).version(version);
-            let callback = (error: GraphError, _response: any, rawResponse?: any) => {
-                if (error) {
-                    reject(error);
-                } else {
-                    resolve(_response);
-                }
-            };
-            await query.update(content, callback);
-        });
-        return p;
-    }
-
-    public static async Post(apiUrl: string, version: string = "v1.0", content: any): Promise<any> {
-        var p = new Promise<string>(async (resolve, reject) => {
-            if (typeof (content) === "object") {
-                content = JSON.stringify(content);
-            }
-
-            let query = this._graphClient.api(apiUrl).version(version);
-            let callback = (error: GraphError, response: any, rawResponse?: any) => {
-                if (error) {
-                    reject(error);
-                } else {
-                    resolve(response);
-                }
-            };
-            await query.post(content, callback);
-        });
-        return p;
-    }
-
-    public static async Delete(apiUrl: string, version: string = "v1.0"): Promise<any> {
-        var p = new Promise<string>(async (resolve, reject) => {
-            let query = this._graphClient.api(apiUrl).version(version);
-            let callback = (error: GraphError, response: any, rawResponse?: any) => {
-                if (error) {
-                    reject(error);
-                } else {
-                    resolve(response);
-                }
-            };
-            await query.delete(callback);
-        });
-        return p;
-    }
-}
+}
\ No newline at end of file
diff --git a/samples/react-graph-cascading-managed-metadata/tsconfig.json b/samples/react-graph-cascading-managed-metadata/tsconfig.json
index e9c60a506..e282e49fb 100644
--- a/samples/react-graph-cascading-managed-metadata/tsconfig.json
+++ b/samples/react-graph-cascading-managed-metadata/tsconfig.json
@@ -25,7 +25,8 @@
       "es5",
       "dom",
       "es2015.collection",
-      "es2015.promise"
+      "es2015.promise",
+      "ES2016.Array.Include"
     ]
   },
   "include": [