code: def test_template_mapper():
      df = pd.DataFrame(
          {
              "prompt": ["prompt sample"],
          }
      )
  
      template = "{prompt}"
      field_names = ["prompt"]
      assert (
          template_mapper(df.iloc[0], field_names, template)
          == "prompt sample"
      )
  
      df_qa = pd.DataFrame(
          {
              "question": ["question sample"],
              "context": ["context sample"],
          }
      )
  
      template_qa = "Context: {context} Question: {question} Answer:"
      field_names_qa = ["context", "question"]
      assert (
          template_mapper(df_qa.iloc[0], field_names_qa, template_qa)
          == "Context: context sample Question: question sample Answer:"
      )
  
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 10 for calling a global function with example usage: test_template_mapper() without return types