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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 set_env(self):
 """Put info about coverage into the env so that subprocesses can activate coverage."""


        if self.cov_source is None:
            os.environ['COV_CORE_SOURCE'] = ''
        else:
            os.environ['COV_CORE_SOURCE'] = UNIQUE_SEP.join(self.cov_source)
        os.environ['COV_CORE_DATA_FILE'] = self.cov_data_file
        os.environ['COV_CORE_CONFIG'] = self.cov_config