Fix for null thumbnail URL

src/Types.ts

@@ -16,7 +16,7 @@ export type Video = {
     outPath: string;
     totalChunks: number;    // Abstraction of FFmpeg timemark
     playbackUrl: string;
-    posterImageUrl: string;
+    posterImageUrl: string | null;
     captionsUrl?: string
 }
 

src/destreamer.ts

@@ -185,8 +185,10 @@ async function downloadVideo(videoGUIDs: Array<string>, outputDirectories: Array
         const headers: string = 'Authorization: Bearer ' + session.AccessToken;
 
         if (!argv.noExperiments) {
+            if (video.posterImageUrl) {
                 await drawThumbnail(video.posterImageUrl, session);
             }
+        }
 
         const ffmpegInpt: any = new FFmpegInput(video.playbackUrl, new Map([
             ['headers', headers]