diff --git a/src/a.ts b/src/a.ts
index 7d3f1ec..79ef0a4 100644
--- a/src/a.ts
+++ b/src/a.ts
@@ -1 +1,3 @@
-console.log(`M365:${process.env.M365_USERNAME}`);
\ No newline at end of file
+import { Env } from "./env";
+console.log(`M365:${process.env.M365_USERNAME}`);
+console.log(`M365B:${Env.username}`);
\ No newline at end of file
diff --git a/src/env.ts b/src/env.ts
new file mode 100644
index 0000000..e57e512
--- /dev/null
+++ b/src/env.ts
@@ -0,0 +1,15 @@
+import * as dotenv from "dotenv";
+dotenv.config();
+
+export class Env {
+  public static get username() {
+    return this.getVal("M365_USERNAME", process.env.M365_USERNAME);
+  }
+
+  private static getVal(name: string, value: string | undefined): string {
+    if (!value) {
+      throw new Error(`Environment variable ${name} should not be empty.`);
+    }
+    return value as string;
+  }
+}
\ No newline at end of file