Improve command system

src/main/java/emu/nebula/command/CommandResult.java

@@ -0,0 +1,19 @@
+package emu.nebula.command;
+
+import lombok.Builder;
+import lombok.Getter;
+
+@Getter
+@Builder
+public class CommandResult {
+    private CommandHandler command;
+    private String message;
+    
+    public boolean isCommandTypeOf(Class<? extends CommandHandler> handler) {
+        if (command == null) {
+            return false;
+        }
+        
+        return command.getClass().equals(handler);
+    }
+}