At-least one leaf configured in container

Hi,

I have a container and which has 3 leafs all are boolean type. All the leafs can be configured in single CLI in sequence.

“container_1 leaf_1 leaf_2 leaf_3”

container container_1 {
tailf:cli-sequence-commands;
tailf:cli-compact-syntax;
  leaf leaf_1 {
    type boolean;
  }
  leaf leaf_2 {
    type boolean;
  }
  leaf leaf_3 {
    type boolean;
  }
}

I have a restriction that at-least one leaf should be present. User can delete max 2 leafs when user tries to delete remaining leaf user should not be allowed. How can i achieve this?

Thanks
Anil

one way could be a must statement for container:

must "./leaf_1 or ./leaf_2 or ./leaf_3";