How to set if a certain department cant view this category in userview with bean shell programming

import java.util.Collection;
import java.util.Map;
import org.joget.apps.app.service.AppUtil;
import org.joget.directory.model.Department;
import org.joget.directory.model.User;
import org.joget.directory.model.service.ExtDirectoryManager;
import org.joget.workflow.model.service.WorkflowUserManager;
import org.joget.workflow.util.WorkflowUtil;

public boolean isAuthorized(User user, Map params) {
    //if no logged in user
    if (user == null) {
        return false;
    }
    
    ExtDirectoryManager directoryManager = (ExtDirectoryManager) AppUtil.getApplicationContext().getBean("directoryManager");
    Collection department = directoryManager.getDepartmentByUsername(user.getUsername());
    
    if(department.equals("Legal")){
        return false;
    }else {
        return true;
    }
}