def METHOD_NAME(f):
    ''' A helper which checks conflicts in sandbox.
    If you try to add twice a file object f with the same name, it shows a warning.
    '''
    fn = f.getPathInSandbox()
    if fn in self.__sandbox_check:
        logger.warning('File %s already in the sandbox (source=%s). Overriding from source=%s',
                       fn, self.__sandbox_check[fn], f.name)
    self.__sandbox_check[fn] = f.name
    return fn