code: def predict(self, x_test, quantile):
      return self.models[quantile].predict(x_test)
  
imports: from typing import Any, Dict, List, Optional, Union
  import copy
  import numpy
  import pandas
  import xgboost
  import gc
  from collections import defaultdict
  from gluonts.core.component import equals, validated
label_desc: Use image node_id 3 for calling the QuantileReg obj's underlying member method code with example usage: obj.predict(x_test, quantile) and returns: self