added a few comments, removed unnecessary function

src/main/java/com/benjocraeft/sharehealth/Commands.java

@@ -5,7 +5,6 @@ import org.bukkit.command.CommandSender;
 import org.bukkit.command.TabExecutor;
 import org.bukkit.entity.Player;
 import org.bukkit.util.StringUtil;
-import org.jetbrains.annotations.NotNull;
 
 import java.util.*;
 import java.util.function.Consumer;
@@ -70,7 +69,7 @@ public class Commands implements TabExecutor {
 
 
     @Override
-    public List<String> onTabComplete(@NotNull CommandSender commandSender, @NotNull Command command, @NotNull String s, String[] strings) {
+    public List<String> onTabComplete(CommandSender commandSender, Command command, String s, String[] strings) {
         List<String> list = new ArrayList<>();
 
         if (strings.length == 1){
@@ -88,7 +87,7 @@ public class Commands implements TabExecutor {
     }
 
     @Override
-    public boolean onCommand(@NotNull CommandSender sender, @NotNull Command cmd, @NotNull String label, String[] args){
+    public boolean onCommand(CommandSender sender, Command cmd, String label, String[] args){
 
         List<String> argList = Arrays.asList(args);
         Pair<Consumer<CommandSender>, String> command = commands.get(argList);

src/main/java/com/benjocraeft/sharehealth/Messenger.java

@@ -47,7 +47,7 @@ public class Messenger {
     }
 
     void onPlayerGotDamageMessage(Player player, double damage, DamageCause cause){
-        String message = damageMessage(player, damage, cause);
+        String message = damageMessage(player, damage, cause.toString());
         playersToSendLogs().forEach(p -> p.sendMessage(message));
     }
 
@@ -61,10 +61,6 @@ public class Messenger {
         playersToSendLogs().forEach(p -> p.sendMessage(message));
     }
 
-    private String damageMessage(Player player, double damage, DamageCause cause){
-        return damageMessage(player, damage, cause.toString());
-    }
-
     private String damageMessage(Player player, double damage, Entity damager){
         String name = damager.getName();
         if (damager instanceof Projectile){

src/main/java/com/benjocraeft/sharehealth/PlayerListeners.java

@@ -14,6 +14,8 @@ import org.bukkit.event.player.PlayerRespawnEvent;
 import org.bukkit.potion.PotionEffect;
 import org.bukkit.potion.PotionEffectType;
 
+import java.util.Arrays;
+
 
 public class PlayerListeners implements Listener{
 
@@ -33,7 +35,8 @@ public class PlayerListeners implements Listener{
         double damage = event.getFinalDamage();
 
         DamageCause cause = event.getCause();
-
+        // not allowed triggering message
+        // because these types trigger an extra event by entity or by block
         DamageCause[] notAllowed = new DamageCause[]{
                 DamageCause.ENTITY_ATTACK,
                 DamageCause.ENTITY_EXPLOSION,
@@ -42,13 +45,7 @@ public class PlayerListeners implements Listener{
         };
 
         if (entity instanceof Player){
-            boolean allowed = true;
-            for (DamageCause damageCause : notAllowed) {
-                if (cause.equals(damageCause)){
-                    allowed = false;
-                    break;
-                }
-            }
+            boolean allowed = !Arrays.asList(notAllowed).contains(cause);
             double absorbedDamage = -event.getOriginalDamage(DamageModifier.ABSORPTION);
             Sharehealth.Instance.onPlayerGotDamage((Player) entity, damage, cause, allowed, absorbedDamage);
         }

src/main/java/com/benjocraeft/sharehealth/Sharehealth.java

@@ -36,6 +36,7 @@ public class Sharehealth extends JavaPlugin {
         return statistics;
     }
 
+    //If isFailed, plugin changes no default behaviours
     boolean isFailed = false;
 
     private final Map<String, Object> defaultStatus = new HashMap<>();