code: def test_warn_low_n_samples():
      df_low = pd.DataFrame(
          {"prompt": ["a"] * 10, "completion": ["b"] * 10}
      )
  
      df_high = pd.DataFrame(
          {"prompt": ["a"] * 100, "completion": ["b"] * 100}
      )
  
      message = "TODO: We would recommend having more samples (>64) if possible but current_file only contains 10 samples. "
      assert warn_low_n_samples(df_low) == message
      assert warn_low_n_samples(df_high) is None
  
imports: import pandas
  import pytest
  from ..customization_dataset_preparation import convert_into_prompt_completion_only, convert_into_template, drop_duplicated_rows, drop_unrequired_fields, get_common_suffix, get_prepared_filename, parse_template, recommend_hyperparameters, show_first_example_in_df, split_into_train_validation, template_mapper, validate_template, warn_and_drop_long_samples, warn_completion_is_not_empty, warn_duplicated_rows, warn_imbalanced_completion, warn_low_n_samples, warn_missing_suffix
label_desc: Use image node_id 16 for calling a global function with example usage: test_warn_low_n_samples() without return types