code: def _enforce_min_instances(x, min_instances=1):
      n_instances = x.shape[0]
      if n_instances < min_instances:
          raise ValueError(
              f"Found array with: {n_instances} instance(s) "
              f"but a minimum of: {min_instances} is required."
          )
  
file_path: sktime/sktime/utils/validation/panel.py
imports: import numpy
  import pandas
  from sklearn.utils.validation import check_consistent_length
  from sktime.datatypes._panel._check import is_nested_dataframe
  from sktime.datatypes._panel._convert import from_3d_numpy_to_nested, from_nested_to_3d_numpy
label_desc: Use image node_id 4 for calling a global function with example usage: _enforce_min_instances(x, min_instances) without return types