code: def timeseries_from_mat(filename, varname=None, fs=1.0):
      
      import scipy.io as sio
      if varname is None:
          mat_dict = sio.loadmat(filename)
          if len(mat_dict) > 1:
              raise ValueError('Must specify varname: file contains '
                               'more than one variable. ')
      else:
          mat_dict = sio.loadmat(filename, variable_names=(varname,))
          array = mat_dict.popitem()[1]
      return Timeseries(array, fs=fs)
docs: load a multi-channel Timeseries from a MATLAB .mat file
  
      Args:
        filename (str): .mat file to load
        varname (str): variable name. only needed if there is more than one
          variable saved in the .mat file
        fs (scalar): sample rate of timeseries in Hz. (constant timestep assumed)
  
      Returns:
        Timeseries