Smaller code improvements

Author: TobiGr

extractor/src/main/java/org/schabi/newpipe/extractor/services/peertube/linkHandler/PeertubeSearchQueryHandlerFactory.java

@@ -35,10 +35,7 @@ public String getUrl(String searchString, List<String> contentFilters, String so
     @Override
     public String getUrl(String searchString, List<String> contentFilters, String sortFilter, String baseUrl) throws ParsingException {
         try {
-            final String url = baseUrl + SEARCH_ENDPOINT
-                    + "?search=" + URLEncoder.encode(searchString, UTF_8);
-
-            return url;
+            return baseUrl + SEARCH_ENDPOINT + "?search=" + URLEncoder.encode(searchString, UTF_8);
         } catch (UnsupportedEncodingException e) {
             throw new ParsingException("Could not encode query", e);
         }

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

@@ -221,6 +221,7 @@ public List<Localization> getSupportedLocalizations() {
         return SUPPORTED_LANGUAGES;
     }
 
+    @Override
     public List<ContentCountry> getSupportedCountries() {
         return SUPPORTED_COUNTRIES;
     }

extractor/src/main/java/org/schabi/newpipe/extractor/stream/StreamInfo.java

@@ -10,6 +10,7 @@
 
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.Locale;
 
@@ -153,11 +154,11 @@ private static StreamInfo extractStreams(StreamInfo streamInfo, StreamExtractor
 
         // Lists can be null if a exception was thrown during extraction
         if (streamInfo.getVideoStreams() == null)
-            streamInfo.setVideoStreams(new ArrayList<VideoStream>());
+            streamInfo.setVideoStreams(Collections.emptyList());
         if (streamInfo.getVideoOnlyStreams() == null)
-            streamInfo.setVideoOnlyStreams(new ArrayList<VideoStream>());
+            streamInfo.setVideoOnlyStreams(Collections.emptyList());
         if (streamInfo.getAudioStreams() == null)
-            streamInfo.setAudioStreams(new ArrayList<AudioStream>());
+            streamInfo.setAudioStreams(Collections.emptyList());
 
         Exception dashMpdError = null;
         if (!isNullOrEmpty(streamInfo.getDashMpdUrl())) {