[Youtube] Add subchannel functions to mix and fix imports

Author: Stypox

extractor/src/main/java/org/schabi/newpipe/extractor/services/youtube/YoutubeService.java

@@ -20,6 +20,7 @@
 import org.schabi.newpipe.extractor.services.youtube.extractors.YoutubeChannelExtractor;
 import org.schabi.newpipe.extractor.services.youtube.extractors.YoutubeCommentsExtractor;
 import org.schabi.newpipe.extractor.services.youtube.extractors.YoutubeFeedExtractor;
+import org.schabi.newpipe.extractor.services.youtube.extractors.YoutubeMixPlaylistExtractor;
 import org.schabi.newpipe.extractor.services.youtube.extractors.YoutubeMusicSearchExtractor;
 import org.schabi.newpipe.extractor.services.youtube.extractors.YoutubePlaylistExtractor;
 import org.schabi.newpipe.extractor.services.youtube.extractors.YoutubeSearchExtractor;

extractor/src/main/java/org/schabi/newpipe/extractor/services/youtube/extractors/YoutubeMixPlaylistExtractor.java

@@ -1,13 +1,7 @@
 package org.schabi.newpipe.extractor.services.youtube.extractors;
 
-import static org.schabi.newpipe.extractor.services.youtube.linkHandler.YoutubeParsingHelper.getJsonResponse;
-import static org.schabi.newpipe.extractor.services.youtube.linkHandler.YoutubeParsingHelper.getUrlFromNavigationEndpoint;
-
 import com.grack.nanojson.JsonArray;
 import com.grack.nanojson.JsonObject;
-import java.io.IOException;
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
 
 import org.schabi.newpipe.extractor.ListExtractor;
 import org.schabi.newpipe.extractor.StreamingService;
@@ -20,6 +14,14 @@
 import org.schabi.newpipe.extractor.stream.StreamInfoItem;
 import org.schabi.newpipe.extractor.stream.StreamInfoItemsCollector;
 
+import java.io.IOException;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+
+import static org.schabi.newpipe.extractor.services.youtube.YoutubeParsingHelper.getJsonResponse;
+import static org.schabi.newpipe.extractor.services.youtube.YoutubeParsingHelper.getUrlFromNavigationEndpoint;
+
 /**
  * A YoutubePlaylistExtractor for a mix (auto-generated playlist). It handles urls in the format of
  * "youtube.com/watch?v=videoId&list=playlistId"
@@ -185,4 +187,22 @@ private String getThumbnailUrlFromPlaylistId(String playlistId) throws ParsingEx
     private String getThumbnailUrlFromVideoId(String videoId) {
         return "https://i.ytimg.com/vi/" + videoId + "/hqdefault.jpg";
     }
+
+    @Nonnull
+    @Override
+    public String getSubChannelName() {
+        return "";
+    }
+
+    @Nonnull
+    @Override
+    public String getSubChannelUrl() {
+        return "";
+    }
+
+    @Nonnull
+    @Override
+    public String getSubChannelAvatarUrl() {
+        return "";
+    }
 }