code: def no_quantile_crossing(
      forecast: QuantileForecast, quantile_levels: List[float]
  ):
      sorted_levels = sorted(quantile_levels)
      quantile = forecast.quantile(sorted_levels[0])
      if np.isnan(quantile).any():
          return False
  
      for level in sorted_levels[1:]:
          prev_quantile = quantile
          quantile = forecast.quantile(level)
          if (quantile < prev_quantile).any():
              return False
  
      return True
  
file_path: gluonts/test/ext/r_forecast/test_r_multi_seasonality.py
imports: from typing import List
  import numpy
  import pandas
  import pytest
  from gluonts.evaluation import Evaluator, backtest_metrics
  from gluonts.ext.r_forecast import R_IS_INSTALLED, RPY2_IS_INSTALLED, RForecastPredictor
  from gluonts.model.forecast import QuantileForecast
label_desc: Use image node_id 1 for calling a global function with example usage: no_quantile_crossing(forecast, quantile_levels) and returns: True, False, False