Add deprecated old method calls to avoid breaking API

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

@@ -337,6 +337,22 @@ public abstract class StreamExtractor extends Extractor {
     public abstract InfoItemsCollector<? extends InfoItem, ? extends InfoItemExtractor>
     getRelatedItems() throws IOException, ExtractionException;
 
+    /**
+     * @deprecated Use {@link #getRelatedItems()}. May be removed in a future version.
+     * @return The result of {@link #getRelatedItems()} if it is a
+     *         StreamInfoItemsCollector, null otherwise
+     * @throws IOException
+     * @throws ExtractionException
+     */
+    @Deprecated
+    @Nullable
+    public StreamInfoItemsCollector getRelatedStreams() throws IOException, ExtractionException {
+        InfoItemsCollector<?, ?> collector = getRelatedItems();
+        if (collector instanceof StreamInfoItemsCollector) {
+            return (StreamInfoItemsCollector) collector;
+        } else return null;
+    }
+
     /**
      * Should return a list of Frameset object that contains preview of stream frames
      *

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

@@ -606,10 +606,26 @@ public class StreamInfo extends Info {
         return relatedItems;
     }
 
+    /**
+     * @deprecated Use {@link #getRelatedItems()}
+     */
+    @Deprecated
+    public List<InfoItem> getRelatedStreams() {
+        return getRelatedItems();
+    }
+
     public void setRelatedItems(List<InfoItem> relatedItems) {
         this.relatedItems = relatedItems;
     }
 
+    /**
+     * @deprecated Use {@link #setRelatedItems(List)}
+     */
+    @Deprecated
+    public void setRelatedStreams(List<InfoItem> relatedItems) {
+        setRelatedItems(relatedItems);
+    }
+
     public long getStartPosition() {
         return startPosition;
     }

extractor/src/main/java/org/schabi/newpipe/extractor/utils/ExtractorHelper.java

@@ -41,4 +41,12 @@ public class ExtractorHelper {
         }
     }
 
+    /**
+     * @deprecated Use {@link #getRelatedItemsOrLogError(StreamInfo, StreamExtractor)}
+     */
+    @Deprecated
+    public static List<InfoItem> getRelatedVideosOrLogError(StreamInfo info, StreamExtractor extractor) {
+        return getRelatedItemsOrLogError(info, extractor);
+    }
+
 }