code: def test_check_input(forecast_result):
      """Tests processing inputs."""
      # Method name wrong.
      with pytest.raises(
          UncertaintyError,
          match=f"The uncertainty method uncertainty_method is not as expected quantile_regression.",
      ):
          model = QuantileRegressionUncertaintyModel(
              uncertainty_dict={
                  "uncertainty_method": "uncertainty_method",
              }
          )
          model.train_df = forecast_result["df"]
          model.x_mat = forecast_result["x_mat"]
          model._check_input()
  
      # Value column not found.
      with pytest.raises(
          UncertaintyError,
          match=f"The parameter value_col is required but not found in",
      ):
          model = QuantileRegressionUncertaintyModel(
              uncertainty_dict={
                  "uncertainty_method": "quantile_regression",
              }
          )
          model.train_df = forecast_result["df"][["ts"]]
          model.x_mat = forecast_result["x_mat"]
          model._check_input()
  
      # Value column not found in df.
      with pytest.raises(
          UncertaintyError,
          match=f"`value_col` col not found in `train_df`.",
      ):
          model = QuantileRegressionUncertaintyModel(
              uncertainty_dict={
                  "uncertainty_method": "quantile_regression",
                  "params": {"value_col": "col"},
              }
          )
          model.train_df = forecast_result["df"]
          model.x_mat = forecast_result["x_mat"]
          model._check_input()
  
      # No time column or ``x_mat``.
      with pytest.raises(
          UncertaintyError,
          match=f"Time column must be provided when `x_mat` is not given.",
      ):
          model = QuantileRegressionUncertaintyModel(
              uncertainty_dict={
                  "uncertainty_method": "quantile_regression",
                  "params": {},
              }
          )
          model.train_df = forecast_result["df"][["y"]]
          model._check_input()
  
file_path: greykite/greykite/tests/sklearn/uncertainty/test_quantile_regression_uncertainty_model.py
imports: import pandas
  import pytest
  from greykite.common import constants
  from greykite.common.data_loader import DataLoader
  from greykite.sklearn.estimator.simple_silverkite_estimator import SimpleSilverkiteEstimator
  from greykite.sklearn.uncertainty.exceptions import UncertaintyError
  from greykite.sklearn.uncertainty.quantile_regression_uncertainty_model import QuantileRegressionUncertaintyModel
label_desc: Use image node_id 3 for calling a global function with example usage: test_check_input(forecast_result) without return types