Can you provide a tutorial for writing the json file to build the composite robot in isaac sim?

Hello there

I have known how to build a composite robot by two URDF files, but I’m confused with the json file provided below

"name": "SegwayWithArms",
   "sources": [
      {
        "id": "segway",
        "path": "segway_description/urdf/segway440LE.urdf",
        "format": "urdf"
      },
      {
        "id": "franka",
        "path": "franka_description/robots/panda_arm.urdf",
        "format": "urdf"
      }
    ],
    "composition": [
      {
        "id": "base",
        "source": "segway"
      },
      {
        "id": "arm1",
        "source": "franka",
        "parent": "base",
        "parent_body": "inertial_collision_link",
        "local_pose": {
          "xyz": "0.3 0 0.265",
          "rpy": "0 0 0"
        }
      },
      {
        "id": "arm2",
        "source": "franka",
        "parent": "base",
        "parent_body": "inertial_collision_link",
        "local_pose": {
          "xyz": "-0.3 0 0.265",
          "rpy": "0 0 3.14159265359"
        }
      }
    ]
  }

In sources label, can we provide the robot model by Blueprint class? In other words,is the format must be the “urdf”?

If it is possible, Can you provide a tutorial for how to write the json file for building the composite robot?

BR