[#11930] Share as YouTube temporary playlist

Initial commit.

app/src/test/java/org/schabi/newpipe/local/playlist/LocalPlaylistFragmentTest.java

@@ -0,0 +1,55 @@
+package org.schabi.newpipe.local.playlist;
+
+import static org.schabi.newpipe.local.playlist.PlayListShareMode.YOUTUBE_TEMP_PLAYLIST;
+
+import androidx.annotation.NonNull;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.schabi.newpipe.database.stream.model.StreamEntity;
+import org.schabi.newpipe.extractor.stream.StreamType;
+
+import java.util.List;
+import java.util.stream.Stream;
+
+public class LocalPlaylistFragmentTest {
+
+    @Test
+    public void youTubeTempPlaylist() {
+
+        Stream<StreamEntity> entityStream = List.of(
+
+            "https://www.youtube.com/watch?v=1"
+           ,"https://www.youtube.com/watch?v=2"
+           ,"https://www.youtube.com/watch?v=3"
+        )
+        .stream()
+        .map(LocalPlaylistFragmentTest::newStreamEntity)
+        ;
+
+        String url = LocalPlaylistFragment.export(YOUTUBE_TEMP_PLAYLIST, entityStream, null);
+
+        Assert.assertEquals("http://www.youtube.com/watch_videos?video_ids=1,2,3", url);
+    }
+
+    @NonNull
+    static StreamEntity newStreamEntity(String url) {
+
+        return new StreamEntity(
+
+              0
+            , 1
+            , url
+            , "Title"
+            , StreamType.VIDEO_STREAM
+            , 100
+            , "Uploader"
+            , null
+            , null
+            , null
+            , null
+            , null
+            , null
+        );
+    }
+}