code: def test_drop_duplicated_rows():
      df_deduplicated = pd.DataFrame(
          {"prompt": ["prompt"], "completion": ["completion"]}
      )
  
      df_duplicated = pd.DataFrame(
          {"prompt": ["prompt"] * 2, "completion": ["completion"] * 2}
      )
      message_duplicated = "There are 1 duplicated rows\n"
      message_duplicated += "Removed 1 duplicate rows"
  
      assert drop_duplicated_rows(df_duplicated)[0].equals(
          df_deduplicated
      )
      assert (
          drop_duplicated_rows(df_duplicated)[1] == message_duplicated
      )
  
      df_unique = pd.DataFrame(
          {
              "prompt": ["prompt", "prompt1"],
              "completion": ["completion", "completion1"],
          }
      )
      assert drop_duplicated_rows(df_unique) == (df_unique, None)
  
      df_only_prompt_duplicated = pd.DataFrame(
          {
              "prompt": ["prompt"] * 2,
              "completion": ["completion", "completion1"],
          }
      )
      assert drop_duplicated_rows(df_only_prompt_duplicated) == (
          df_only_prompt_duplicated,
          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 9 for calling a global function with example usage: test_drop_duplicated_rows() without return types