message: Changing the conditional expression to check for undefined or null headers
diff: @@ -310,7 +310,7 @@ export class GraphRequest {
  * @returns nothing
  */
  private setHeaderContentType(): void {
  - if (this._headers === undefined || this._headers === null) {
  + if (!this._headers) {
  this.header("Content-Type", "application/json");
  }
  let isContentTypePresent = false;
  