code: def load(self, env=None):
          
          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)
docs: 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