Made some changes and fixes to commands

ArgumentHandler#tabComplete(CommandSender, String[]) now returns a
Set<String>
Removed some redundant code

src/main/java/us/tastybento/bskyblock/api/commands/AbstractCommand.java

@@ -1,24 +1,15 @@
 package us.tastybento.bskyblock.api.commands;
 
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import java.util.UUID;
-
 import org.bukkit.command.Command;
 import org.bukkit.command.CommandExecutor;
 import org.bukkit.command.CommandSender;
 import org.bukkit.command.TabCompleter;
 import org.bukkit.entity.Player;
-
 import us.tastybento.bskyblock.BSkyBlock;
 import us.tastybento.bskyblock.util.Util;
 
+import java.util.*;
+
 /**
  *
  * @author Poslovitch
@@ -63,7 +54,7 @@ public abstract class AbstractCommand implements CommandExecutor, TabCompleter {
                 }
 
                 @Override
-                public List<String> tabComplete(CommandSender sender, String[] args) {
+                public Set<String> tabComplete(CommandSender sender, String[] args) {
                     return null; // No tab options for this one
                 }
 
@@ -84,7 +75,7 @@ public abstract class AbstractCommand implements CommandExecutor, TabCompleter {
     public interface ArgumentHandler {
         CanUseResp canUse(CommandSender sender);
         void execute(CommandSender sender, String[] args);
-        List<String> tabComplete(CommandSender sender, String[] args);
+        Set<String> tabComplete(CommandSender sender, String[] args);
         String[] usage(CommandSender sender);
     }
 
@@ -187,7 +178,7 @@ public abstract class AbstractCommand implements CommandExecutor, TabCompleter {
                 ArgumentHandler handler = getHandler(args[0]);
                 if (handler != null && handler.canUse(sender).isAllowed()) {
                     // We remove the 1st arg - and remove any blank args caused by hitting space before the tab
-                    List<String> tabOptions = handler.tabComplete(sender, clean(Arrays.copyOfRange(args, 1, args.length)));
+                    Set<String> tabOptions = handler.tabComplete(sender, clean(Arrays.copyOfRange(args, 1, args.length)));
                     if (tabOptions != null) options.addAll(tabOptions);
                 }
             }

src/main/java/us/tastybento/bskyblock/commands/AdminCommand.java

@@ -5,7 +5,7 @@ import us.tastybento.bskyblock.BSkyBlock;
 import us.tastybento.bskyblock.api.commands.AbstractCommand;
 import us.tastybento.bskyblock.config.Settings;
 
-import java.util.List;
+import java.util.Set;
 
 public class AdminCommand extends AbstractCommand {
     
@@ -35,7 +35,7 @@ public class AdminCommand extends AbstractCommand {
             }
 
             @Override
-            public List<String> tabComplete(CommandSender sender, String[] args) {
+            public Set<String> tabComplete(CommandSender sender, String[] args) {
                 // TODO Auto-generated method stub
                 return null;
             }