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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 load(self, env=None):
 """ Load a section values of given environment. If nothing to specified, use environmental variable. If unknown environment was specified, warn it on logger. :param env: environment key to load in a coercive manner :type env: string :rtype: dict """

        self._load()
        e = env or \
            os.environ.get(RUNNING_MODE_ENVKEY, DEFAULT_RUNNING_MODE)
        if e in self.config:
            return self.config[e]
        logging.warn("Environment '%s' was not found.", e)