code: def is_flat(obj):
      """Check whether list or tuple is flat, returns true if yes, false if nested."""
      return not any(isinstance(x, (list, tuple)) for x in obj)
  
imports: from inspect import isclass
  import numpy
  import pandas
  from sktime.base import BaseEstimator
label_desc: Use image node_id 4 for calling a global function with example usage: is_flat(obj) and returns: unknown