def swflux_adjustment(file: str, group_files: str, cdo, options, verbose,
    include_precip=False, **kwargs):
    """
    Calculate surface fresh water flux
    :param preprocessor: PreProcessor object, contains a lot of necessary adjustments
    :param file: file which contains all necessary parameters to calculate dQdSST
    :param group_files: list of all files which contain necessary parameters to calculate dQdSST
    :param flags: any extra info necessary
    :return:
    """
    if verbose:
        print('Adjusting for swflux')
    temp = cdo.setattribute(
        "swflux@long_name='surface fresh water flux',swflux@unit='cm day-1',swflux@files='"
         + group_files + "'", input='-delname,evap' + (',precip' if not
        include_precip else '') + " -aexpr,'swflux=precip+evap' " + file,
        options=options)
    cdo.copy(input=temp, output=file, options=options)
    if verbose:
        print('swflux has been added')
