diff --git a/src/main/java/com/github/kisaragieffective/signpictureported/InternalSpecialUtility.java b/src/main/java/com/github/kisaragieffective/signpictureported/InternalSpecialUtility.java
index 88ee981..7f8cad8 100644
--- a/src/main/java/com/github/kisaragieffective/signpictureported/InternalSpecialUtility.java
+++ b/src/main/java/com/github/kisaragieffective/signpictureported/InternalSpecialUtility.java
@@ -1,7 +1,6 @@
 package com.github.kisaragieffective.signpictureported;
 
 import net.minecraft.block.entity.SignBlockEntity;
-import net.minecraft.client.texture.NativeImage;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.util.JsonHelper;
 
@@ -22,7 +21,7 @@ private static List<String> lineTags(CompoundTag dest) {
         ));
     }
 
-    public static <T> T dummy() {
+    public static <T> T never() {
         throw new AssertionError("This statement shouldn't reached!");
     }
 
@@ -51,34 +50,8 @@ public static List<String> getPlaintextLines(SignBlockEntity sbe) {
                 .collect(Collectors.toList());
     }
 
-    /**
-     * Flip horizontally. This method is in-place.
-     * Converts
-     * <pre>
-     * 1 2 3
-     * 4 5 6
-     * 7 8 9
-     * </pre>
-     * to
-     * <pre>
-     * 3 2 1
-     * 6 5 4
-     * 9 8 7
-     * </pre>
-     * where 1 to 9 are its pixels.
-     * @param ni
-     * @return the flipped image
-     */
-    public static NativeImage mirrorHorizontally(NativeImage ni) {
-        for (int y = 0; y < ni.getHeight(); y++) {
-            for (int x = 0; x < ni.getWidth() / 2; x++) {
-                int color1 = ni.getPixelColor(x, y);
-                final int destX1 = ni.getWidth() - 1 - x;
-                int color2 = ni.getPixelColor(destX1, y);
-                ni.setPixelColor(destX1, y, color1);
-                ni.setPixelColor(x, y, color2);
-            }
-        }
-        return ni;
+    @SuppressWarnings("unchecked")
+    public static <T> T implicitCast(Object o) {
+        return (T) o;
     }
 }
diff --git a/src/main/java/com/github/kisaragieffective/signpictureported/mixin/SignBlockEntityRenderMixin.java b/src/main/java/com/github/kisaragieffective/signpictureported/mixin/SignBlockEntityRenderMixin.java
index 99e198d..b815f4d 100644
--- a/src/main/java/com/github/kisaragieffective/signpictureported/mixin/SignBlockEntityRenderMixin.java
+++ b/src/main/java/com/github/kisaragieffective/signpictureported/mixin/SignBlockEntityRenderMixin.java
@@ -26,19 +26,21 @@
 import org.spongepowered.asm.mixin.injection.Inject;
 import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
 
+import java.io.BufferedInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.UncheckedIOException;
 import java.lang.ref.SoftReference;
 import java.net.HttpURLConnection;
 import java.net.MalformedURLException;
-import java.net.URI;
 import java.net.URL;
-import java.net.http.HttpClient;
-import java.net.http.HttpRequest;
-import java.net.http.HttpResponse;
 import java.util.*;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
+import java.util.function.Supplier;
 
-import static com.github.kisaragieffective.signpictureported.InternalSpecialUtility.dummy;
+import static com.github.kisaragieffective.signpictureported.InternalSpecialUtility.implicitCast;
+import static com.github.kisaragieffective.signpictureported.InternalSpecialUtility.never;
 
 @Mixin(SignBlockEntityRenderer.class)
 public class SignBlockEntityRenderMixin {
@@ -280,7 +282,7 @@ private NativeImageBackedTexture registerFrom(URL url) {
             try {
                 HttpURLConnection huc1;
                 if (url.getHost() == null || url.getProtocol() == null) return null;
-                huc1 = cast(url.openConnection());
+                huc1 = implicitCast(url.openConnection());
                 huc1.setInstanceFollowRedirects(true);
                 huc1.connect();
                 final int code = huc1.getResponseCode();