Extract nullable stream to new util class.

src/hdskins/java/com/voxelmodpack/hdskins/HDSkinManager.java

@@ -26,6 +26,7 @@ import com.voxelmodpack.hdskins.skins.ServerType;
 import com.voxelmodpack.hdskins.skins.SkinServer;
 import com.voxelmodpack.hdskins.skins.ValhallaSkinServer;
 import com.voxelmodpack.hdskins.util.CallableFutures;
+import com.voxelmodpack.hdskins.util.MoreStreams;
 import com.voxelmodpack.hdskins.util.PlayerUtil;
 import com.voxelmodpack.hdskins.util.ProfileTextureUtil;
 import net.minecraft.client.Minecraft;
@@ -288,7 +289,7 @@ public final class HDSkinManager implements IResourceManagerReloadListener {
     }
 
     private Stream<NetworkPlayerInfo> getNPCs(Minecraft mc) {
-        return nullableStream(mc.world)
+        return MoreStreams.ofNullable(mc.world)
                 .flatMap(w -> w.playerEntities.stream())
                 .filter(AbstractClientPlayer.class::isInstance)
                 .map(AbstractClientPlayer.class::cast)
@@ -296,14 +297,10 @@ public final class HDSkinManager implements IResourceManagerReloadListener {
     }
 
     private Stream<NetworkPlayerInfo> getPlayers(Minecraft mc) {
-        return nullableStream(mc.getConnection())
+        return MoreStreams.ofNullable(mc.getConnection())
                 .flatMap(a -> a.getPlayerInfoMap().stream());
     }
 
-    private static <T> Stream<T> nullableStream(@Nullable T t) {
-        return t == null ? Stream.empty() : Stream.of(t);
-    }
-
     public void parseSkin(GameProfile profile, Type type, ResourceLocation resource, MinecraftProfileTexture texture) {
 
         CallableFutures.scheduleTask(() -> {

src/hdskins/java/com/voxelmodpack/hdskins/util/MoreStreams.java

@@ -0,0 +1,11 @@
+package com.voxelmodpack.hdskins.util;
+
+import java.util.stream.Stream;
+import javax.annotation.Nullable;
+
+public class MoreStreams {
+
+    public static <T> Stream<T> ofNullable(@Nullable T t) {
+        return t == null ? Stream.empty() : Stream.of(t);
+    }
+}