code: def sequential(self, func, args_dict=None):
          
          for uri, cf in self._cfs.items():
              args = self._process_args_dict(cf, uri, args_dict)
              func(*args)
docs: Execute a function for all Crazyflies in the swarm, in sequence.
  
          The first argument of the function that is passed in will be a
          SyncCrazyflie instance connected to the Crazyflie to operate on.
          A list of optional parameters (per Crazyflie) may follow defined by
          the args_dict. The dictionary is keyed on URI.
  
          Example:
          def my_function(scf, optional_param0, optional_param1)
              ...
  
          args_dict = {
              URI0: [optional_param0_cf0, optional_param1_cf0],
              URI1: [optional_param0_cf1, optional_param1_cf1],
              ...
          }
  
  
          self.sequential(my_function, args_dict)
  
          :param func: the function to execute
          :param args_dict: parameters to pass to the function