[Groovy] how to check Jira User in any group workflow validation

how  to check Jira User in any group groovy sccript workflow validation

import com.atlassian.jira.component.ComponentAccessor
import com.atlassian.jira.user.ApplicationUser
import com.atlassian.jira.security.groups.GroupManager

ApplicationUser appUser = ComponentAccessor.getJiraAuthenticationContext().getLoggedInUser();
GroupManager groupManager = ComponentAccessor.getGroupManager();
Collection<String> groupNames = groupManager.getGroupNamesForUser(appUser.getDirectoryUser().getName());

passesCondition =false;
for( String gName : groupNames ){
    if( gName == "DummyGroup" ){
        passesCondition = true;

    }
}