{
  "ballsNr": 50,

  "ball":
  {
    "r":  {"@some": "int", "min":  8, "max":  15},
    "x":  {"@some": "int", "min": 20, "max": 380},
    "y":  {"@some": "int", "min": 20, "max": 280},
    "vx": {"@some":
           [{"@some": "int", "min": -30, "max": -80},
            {"@some": "int", "min":  30, "max":  80}
           ]
          },
    "vy": {"@some":
           [{"@some": "int", "min": -30, "max": -80},
            {"@some": "int", "min":  30, "max":  80}
           ]
          }
  }
}