code: func (b PolicyBindings) Clone() PolicyBindings {
  	clone := make(PolicyBindings, len(b))
  	for role, members := range b {
  		membersCopy := make(membersSet, len(members))
  		for k, v := range members {
  			membersCopy[k] = v
  		}
  		clone[role] = membersCopy
  	}
  	return clone
  }
docs: // Clone makes a deep copy of this object.