code: def _std_tuple_of(var=None, std=None, interval=None):
      
  
      if std is not None:
          if np.isscalar(std):
              std = (std,)
          return std
  
  
      if interval is not None:
          if np.isscalar(interval):
              interval = (interval,)
  
          return norm.interval(interval)[1]
  
      if var is None:
          raise ValueError("no inputs were provided")
  
      if np.isscalar(var):
          var = (var,)
      return np.sqrt(var)
docs: Convienence function for plotting. Given one of var, standard
      deviation, or interval, return the std. Any of the three can be an
      iterable list.
  
      Examples
      --------
      >>>_std_tuple_of(var=[1, 3, 9])
      (1, 2, 3)