Finish implementing CompoundTag

lib/nbt/impl/ByteArrayTag.dart

@@ -3,10 +3,17 @@ import 'package:libac_flutter/nbt/Tag.dart';
 
 class ByteArrayTag extends Tag {
   List<int> _value = [];
-  ByteArrayTag(List<int> value) {
+
+  ByteArrayTag();
+
+  ByteArrayTag._(List<int> value) {
     _value.addAll(value);
   }
 
+  static ByteArrayTag valueOf(List<int> value) {
+    return ByteArrayTag._(value);
+  }
+
   @override
   void readValue(ByteLayer data) {
     int len = data.readInt();

lib/nbt/impl/ByteTag.dart

@@ -4,10 +4,16 @@ import 'package:libac_flutter/nbt/Tag.dart';
 class ByteTag extends Tag {
   int _value = 0;
 
-  ByteTag(int value) {
+  ByteTag._(int value) {
     _value = value;
   }
 
+  ByteTag();
+
+  static ByteTag valueOf(int value) {
+    return ByteTag._(value);
+  }
+
   @override
   void readValue(ByteLayer data) {
     _value = data.readByte();

lib/nbt/impl/CompoundTag.dart

@@ -1,21 +1,37 @@
 import 'package:libac_flutter/nbt/Stream.dart';
 import 'package:libac_flutter/nbt/Tag.dart';
 
-class TagCompound extends Tag {
+class CompoundTag extends Tag {
   late final Map<String, Tag> _value;
 
-  TagCompound() {
+  CompoundTag() {
     _value = new Map();
   }
 
   @override
   void readValue(ByteLayer data) {
-    // TODO: implement readValue
+    _value.clear();
+
+    while (true) {
+      Tag tag = Tag.readNamedTag(data);
+      if (tag.getType() == 0) {
+        return;
+      }
+
+      put(tag.getKey(), tag);
+    }
   }
 
   @override
   void writeValue(ByteLayer data) {
-    // TODO: implement writeValue
+    Iterator<Tag> it = _value.values.iterator;
+
+    while (it.moveNext()) {
+      Tag tag = it.current;
+      Tag.writeNamedTag(tag, data);
+    }
+
+    data.writeByte(TagType.End.byte);
   }
 
   void put(String name, Tag tag) {