code: def format(input, **params):
      
      PARAM_FORMAT_STRING = 'format.string'
      PARAM_FORMAT_INPUT = 'format.input'
      PARAM_RESULT_FIELD = 'result.field'
      IN_DESC_FIELD = 'field'
      IN_DESC_TYPE = 'type'
  
      format_string = params.get(PARAM_FORMAT_STRING)
      format_inputs = params.get(PARAM_FORMAT_INPUT)
      result_field = params.get(PARAM_RESULT_FIELD)
      for row in input:
          row_input = []
          for desc in format_inputs:
              row_input.append(Converter.convert(row[desc[IN_DESC_FIELD]], desc[IN_DESC_TYPE]))
          row[result_field] = format_string.format(*row_input)
      return input
docs: Appends string formatted value to result
      :param input:
      :param params:
      :return: