Using Class instead of HashMap, removed downloadSubtitles method

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

@@ -426,14 +426,17 @@ public class YoutubeStreamExtractor extends StreamExtractor {
         JsonObject playerConfig = getPlayerConfig(getPageHtml());
         String playerResponse = playerConfig.getObject("args").getString("player_response");
 
+        // Captions does not exist, return null
         if (!JsonParser.object().from(playerResponse).has("captions")) return null;
 
         JsonObject captions = JsonParser.object().from(playerResponse).getObject("captions");
         JsonArray captionsArray = captions.getObject("playerCaptionsTracklistRenderer").getArray("captionTracks");
 
         int captionsSize = captionsArray.size();
-        Subtitles[] result = new Subtitles[captionsSize];
+        // Should not happen, if there is the "captions" object, it should always has some captions in it
+        if(captionsSize == 0) return null;
 
+        Subtitles[] result = new Subtitles[captionsSize];
         for (int x = 0; x < captionsSize; x++) {
             String baseUrl = captionsArray.getObject(x).getString("baseUrl");
 
@@ -447,7 +450,7 @@ public class YoutubeStreamExtractor extends StreamExtractor {
 
             result[x] = new Subtitles(languageName, languageCode, URL, isAutoGenerated);
         }
-         
+
         return result;
     }
 

src/test/java/org/schabi/newpipe/extractor/services/soundcloud/SoundcloudStreamExtractorDefaultTest.java

@@ -105,6 +105,6 @@ public class SoundcloudStreamExtractorDefaultTest {
 
     @Test
     public void testGetSubtitles() throws IOException, ExtractionException, JsonParserException {
-        assertTrue(extractor.getSubtitlesList() != null);
+        assertTrue(extractor.getSubtitles() != null);
     }
 }

src/test/java/org/schabi/newpipe/extractor/services/youtube/YoutubeStreamExtractorDefaultTest.java

@@ -153,17 +153,7 @@ public class YoutubeStreamExtractorDefaultTest {
 
     @Test
     public void testGetSubtitlesList() throws IOException, ExtractionException, JsonParserException {
-        assertTrue(extractor.getSubtitlesList() != null);
-    }
-
-    @Test
-    public void testDownloadSubtitles() throws Exception {
-        try {
-            extractor.downloadSubtitles(extractor.getSubtitlesList().get("en")[0]);
-            // Video has no subtitles!
-            assert false;
-        } catch (Exception e) {
-            assert true;
-        }
+        // Video (/view?v=YQHsXMglC9A) set in the setUp() method has no captions => null
+        assertTrue(extractor.getSubtitles() != null);
     }
 }

src/test/java/org/schabi/newpipe/extractor/services/youtube/YoutubeStreamExtractorRestrictedTest.java

@@ -107,11 +107,6 @@ public class YoutubeStreamExtractorRestrictedTest {
 
     @Test
     public void testGetSubtitlesList() throws IOException, ExtractionException, JsonParserException {
-        assertTrue(extractor.getSubtitlesList() != null);
-    }
-
-    @Test
-    public void testDownloadSubtitles() throws Exception {
-        assertTrue(extractor.downloadSubtitles("https://youtu.be/FmG385_uUys?t=174") != null);
+        assertTrue(extractor.getSubtitles() != null);
     }
 }