docs: def _get_transformers(self):
          """Load the contents of meta_file and extract information about the transformers.
  
          Returns:
              dict: tuple(str, str) -> Transformer.
          """
          transformer_dict = {}
  
          for table in self.metadata['tables']:
              table_name = table['name']
  
              for field in table['fields']:
                  transformer_type = field.get('type')
                  if transformer_type:
                      col_name = field['name']
                      transformer_dict[(table_name, col_name)] = transformer_type
  
          return transformer_dict