code: def warn_low_n_samples(df, min_samples=64):
      if len(df) < min_samples:
          return f"""TODO: We would recommend having more samples (>{min_samples}) if possible but current_file only contains {len(df)} samples. """
      return None
  
imports: import argparse
  import math
  import os
  import pathlib
  from collections import Counter
  import numpy
  import pandas
label_desc: Use image node_id 18 for calling a global function with example usage: warn_low_n_samples(df, min_samples) and returns: None, str, min_samples, str, len, str