Flesh out NBT types

mcmmo-core/src/main/java/com/gmail/nossr50/core/nbt/NBTByte.java

@@ -25,4 +25,5 @@ public class NBTByte implements NBTBase {
     public void setValue(Byte value) {
         this.value = value;
     }
+
 }

mcmmo-core/src/main/java/com/gmail/nossr50/core/nbt/NBTList.java

@@ -4,7 +4,6 @@ import java.util.List;
 
 public class NBTList implements NBTBase {
 
-    private int length;
     private String key;
     private List<? extends NBTBase> values;
 
@@ -14,7 +13,7 @@ public class NBTList implements NBTBase {
     }
 
     public int getLength() {
-        return length;
+        return values.size();
     }
 
     public String getKey() {

mcmmo-core/src/main/java/com/gmail/nossr50/core/nbt/NBTTagCompound.java

@@ -1,11 +1,19 @@
 package com.gmail.nossr50.core.nbt;
 
+import java.util.Collection;
+import java.util.LinkedHashMap;
 import java.util.Map;
+import java.util.Set;
 
 public class NBTTagCompound implements NBTBase {
 
+    private String key;
     private Map<String, NBTBase> tagMap;
 
+    public NBTTagCompound(String key) {
+        tagMap = new LinkedHashMap<>();
+    }
+
     @Override
     public NBTType getNBTType() {
         return NBTType.COMPOUND;
@@ -15,4 +23,32 @@ public class NBTTagCompound implements NBTBase {
         return tagMap.get(key);
     }
 
+    public String getKey() {
+        return key;
     }
+
+    public void setKey(String key) {
+        this.key = key;
+    }
+
+    public void addNBT(String tagKey, NBTBase nbt) {
+        tagMap.put(tagKey, nbt);
+    }
+
+    public Collection<NBTBase> getMapValues() {
+        return tagMap.values();
+    }
+
+    public Set<String> getMapKeys() {
+        return tagMap.keySet();
+    }
+
+    public int getMapSize() {
+        return tagMap.size();
+    }
+
+    public void removeEntry(String tagKey) {
+        tagMap.remove(tagKey);
+    }
+}
+