A question about empty container not showing

When I use restconf in Sodium-SR1, I find one thing, if I create one container without set value to any child in it, It does not show up.

For example, there is following yang structure:

container A {

  leaf B {
    type string;
  }

  container C {
    // .....
  }
  container D {
    // .....
  }
}

When I new A, set value to B, and just new C, D. And then query root node A, the results are as follows:

"A": {
  "B": "123456"
}

C and D are not shown. So I just want to kown, can we display these empty containers that have been created?