Initial port to 1.16.2

src/main/java/appeng/mixins/structure/BiomeAccessor.java

@@ -0,0 +1,26 @@
+package appeng.mixins.structure;
+
+import java.util.List;
+import java.util.Map;
+
+import net.minecraft.world.gen.feature.structure.Structure;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.gen.Accessor;
+
+import net.minecraft.world.biome.Biome;
+import net.minecraft.world.gen.feature.StructureFeature;
+
+/**
+ * Allows access to the copy of _all_ structures that is maintained within each
+ * instance of {@link Biome}, in order to add our new structure to it. Note that
+ * this does not mean the structure will start _generating_ in this biome, it
+ * will only continue to generate if an adjacent biome has started the structure
+ * and it extends into this one.
+ */
+@Mixin(Biome.class)
+public interface BiomeAccessor {
+
+    @Accessor
+    Map<Integer, List<Structure<?>>> getField_242421_g();
+
+}