Appends string formatted value to result
    :param input:
    :param params:
    :return:

def format(input, **params):
    """
    Appends string formatted value to result
    :param input:
    :param params:
    :return:
    """
    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