remove some java warnings

src/main/java/de/bixilon/minosoft/game/datatypes/Statistics.java

@@ -69,7 +69,7 @@ public enum Statistics {
     STAT_ANIMALS_BRED(new Identifier("stat.animalsBred")),
     STAT_PLAYER_KILLS(new Identifier("stat.playerKills")),
     STAT_FISH_CAUGHT(new Identifier("stat.fishCaught")),
-    STAT_JUN_KFISHED(new Identifier("stat.junkFished")),
+    STAT_JUNK_FISHED(new Identifier("stat.junkFished")),
     STAT_TREASURE_FISHED(new Identifier("stat.treasureFished")),
 
     ;

src/main/java/de/bixilon/minosoft/game/datatypes/entities/EntityProperty.java

@@ -20,7 +20,7 @@ import java.util.UUID;
 
 public class EntityProperty {
     final double value;
-    HashMap<UUID, EntityPropertyModifier> modifiers = new HashMap<>();
+    final HashMap<UUID, EntityPropertyModifier> modifiers = new HashMap<>();
 
     public EntityProperty(double value) {
         this.value = value;

src/main/java/de/bixilon/minosoft/game/datatypes/entities/meta/EntityMetaData.java

@@ -289,7 +289,7 @@ public class EntityMetaData {
         int getId();
     }
 
-    public class MetaDataSet {
+    public static class MetaDataSet {
         final int index;
         final Object data;
 

src/main/java/de/bixilon/minosoft/game/datatypes/scoreboard/ScoreboardTeam.java

@@ -25,7 +25,7 @@ public class ScoreboardTeam {
     String prefix;
     String suffix;
     PacketScoreboardTeams.ScoreboardFriendlyFire friendlyFire;
-    List<String> players;
+    final List<String> players;
 
     public ScoreboardTeam(String name, String displayName, String prefix, String suffix, PacketScoreboardTeams.ScoreboardFriendlyFire friendlyFire, String[] players) {
         this.name = name;

src/main/java/de/bixilon/minosoft/protocol/packets/clientbound/play/PacketEntityProperties.java

@@ -27,7 +27,7 @@ import java.util.UUID;
 
 public class PacketEntityProperties implements ClientboundPacket {
     int entityId;
-    HashMap<EntityPropertyKey, EntityProperty> properties = new HashMap<>();
+    final HashMap<EntityPropertyKey, EntityProperty> properties = new HashMap<>();
 
 
     @Override

src/main/java/de/bixilon/minosoft/protocol/packets/clientbound/play/PacketMapData.java

@@ -163,7 +163,7 @@ public class PacketMapData implements ClientboundPacket {
         }
     }
 
-    public class MapPlayerSet {
+    public static class MapPlayerSet {
         final int type;
         final MapPlayerDirection direction;
         byte x;

src/main/java/de/bixilon/minosoft/protocol/packets/clientbound/play/PacketPlayerInfo.java

@@ -30,7 +30,7 @@ import java.util.List;
 import java.util.UUID;
 
 public class PacketPlayerInfo implements ClientboundPacket {
-    List<PlayerInfoBulk> infos = new ArrayList<>();
+    final List<PlayerInfoBulk> infos = new ArrayList<>();
 
 
     @Override

src/main/java/de/bixilon/minosoft/protocol/protocol/Protocol.java

@@ -25,7 +25,7 @@ import java.util.HashMap;
 import java.util.Map;
 
 public abstract class Protocol implements ProtocolInterface {
-    static HashMap<Packets.Clientbound, Class<? extends ClientboundPacket>> packetClassMapping = new HashMap<>();
+    static final HashMap<Packets.Clientbound, Class<? extends ClientboundPacket>> packetClassMapping = new HashMap<>();
 
 
     public final HashMap<Packets.Serverbound, Integer> serverboundPacketMapping;

src/main/java/de/bixilon/minosoft/protocol/protocol/ProtocolVersion.java

@@ -26,9 +26,9 @@ public enum ProtocolVersion {
     VERSION_1_14_4(new Protocol_1_14_4()),
     VERSION_1_15_2(new Protocol_1_15_2());
 
-    public static TreeMap<Integer, ProtocolVersion> versionMapping = new TreeMap<>();
+    public static final TreeMap<Integer, ProtocolVersion> versionMapping = new TreeMap<>();
 
-    public static ProtocolVersion[] versionMappingArray;
+    public static final ProtocolVersion[] versionMappingArray;
 
     static {
         for (ProtocolVersion v : values()) {