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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_variable_for_feature(self, feature_key, variable_key):
 """ Get the variable with the given variable key for the given feature. Args: feature_key: The key of the feature for which we are getting the variable. variable_key: The key of the variable we are getting. Returns: Variable with the given key in the given variation. """

    feature = self.feature_key_map.get(feature_key)
    if not feature:
      self.logger.error('Feature with key "%s" not found in the datafile.' % feature_key)
      return None

    if variable_key not in feature.variables:
      self.logger.error('Variable with key "%s" not found in the datafile.' % variable_key)
      return None

    return feature.variables.get(variable_key)