code: def get_rejected_variables(self, threshold=0.9):
          
          variable_profile = self.description_set['variables']
          result = []
          if hasattr(variable_profile, 'correlation'):
              result = variable_profile.index[variable_profile.correlation > threshold].tolist()
          return  result
docs: Return a list of variable names being rejected for high
          correlation with one of remaining variables.
  
          Parameters:
          ----------
          threshold : float
              Correlation value which is above the threshold are rejected
          
          Returns
          -------
          list
              The list of rejected variables or an empty list if the correlation has not been computed.