code: def vm2json(vm):
      
      d = {"name": "root", "children": []}
  
      for _class in vm.get_classes():
          c_class = {"name": _class.get_name(), "children": []}
  
          for method in _class.get_methods():
              c_method = {"name": method.get_name(), "children": []}
  
              c_class["children"].append(c_method)
  
          d["children"].append(c_class)
  
      return json.dumps(d)
docs: Get a JSON representation of a DEX file
  
      :param vm: :class:`~androguard.core.bytecodes.dvm.DalvikVMFormat`
      :return: