code: def create_channels(chan_name=None, n_chan=None):
      
      if chan_name is not None:
          n_chan = len(chan_name)
  
      elif n_chan is not None:
          chan_name = _make_chan_name(n_chan)
  
      else:
          raise TypeError('You need to specify either the channel names (chan_name) or the number of channels (n_chan)')
  
      xyz = round(random.randn(n_chan, 3) * 10, decimals=2)
      return Channels(chan_name, xyz)
docs: Create instance of Channels with random xyz coordinates
  
      Parameters
      ----------
      chan_name : list of str
          names of the channels
      n_chan : int
          if chan_name is not specified, this defines the number of channels
  
      Returns
      -------
      instance of Channels
          where the location of the channels is random