code: def placement_group_setup(group_name):
    
  
    existing_placement_groups = u.get_placement_group_dict()
  
    group = existing_placement_groups.get(group_name, None)
    if group:
      assert group.state == 'available'
      assert group.strategy == 'cluster'
      print("Reusing group ", group.name)
      return group
  
    print("Creating group " + group_name)
    ec2 = u.get_ec2_resource()
    group = ec2.create_placement_group(GroupName=group_name, Strategy='cluster')
    return group
docs: Creates placement_group group if necessary. Returns True if new placement_group
    group was created, False otherwise.