code: def test_get_children_left(spark_dtree):
      assert np.array_equal(
          spark_dtree.get_children_left(),
          np.array(
              [
                  1,
                  2,
                  3,
                  -1,
                  -1,
                  -1,
                  7,
                  8,
                  9,
                  -1,
                  -1,
                  -1,
                  13,
                  14,
                  -1,
                  -1,
                  -1,
              ]
          ),
      )
  
imports: import numpy
  import pyspark
  import pytest
  from pyspark.ml.classification import DecisionTreeClassificationModel
  from pyspark.sql import SparkSession
  from dtreeviz.models.spark_decision_tree import ShadowSparkTree
label_desc: Use image node_id 5 for calling a global function with example usage: test_get_children_left(spark_dtree) without return types