Preserve order in SetConverter.

This commit fixes an issue where the order of elements in a set is not preserved when converting elements of the set.

Closes #1969.
Original pull request: #1968.

Author: christophstrobl

src/main/java/org/springframework/data/redis/connection/convert/SetConverter.java

@@ -15,7 +15,6 @@
  */
 package org.springframework.data.redis.connection.convert;
 
-import java.util.HashSet;
 import java.util.LinkedHashSet;
 import java.util.Set;
 import java.util.stream.Collectors;
@@ -24,7 +23,7 @@
 import org.springframework.util.Assert;
 
 /**
- * Converts a Set of values of one type to a Set of values of another type
+ * Converts a Set of values of one type to a Set of values of another type preserving item order.
  *
  * @author Jennifer Hickey
  * @author Christoph Strobl
@@ -50,9 +49,7 @@ public SetConverter(Converter<S, T> itemConverter) {
 	 */
 	@Override
 	public Set<T> convert(Set<S> source) {
-
-		return source.stream().map(itemConverter::convert)
-				.collect(Collectors.toCollection(source instanceof LinkedHashSet ? LinkedHashSet::new : HashSet::new));
+		return source.stream().map(itemConverter::convert).collect(Collectors.toCollection(LinkedHashSet::new));
 	}
 
 }