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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_os_file_names(files):
 """ returns file names :param files: list of strings and\\or :class:`file_configuration_t` instances. :type files: list """


        fnames = []
        for f in files:
            if utils.is_str(f):
                fnames.append(f)
            elif isinstance(f, file_configuration_t):
                if f.content_type in (
                        file_configuration_t.CONTENT_TYPE.STANDARD_SOURCE_FILE,
                        file_configuration_t.CONTENT_TYPE.CACHED_SOURCE_FILE):

                    fnames.append(f.data)
            else:
                pass
        return fnames