code: def test_get_node_samples(spark_dtree):
      assert len(spark_dtree.get_node_samples()[0]) == 891
      assert len(spark_dtree.get_node_samples()[2]) == 18
      assert len(spark_dtree.get_node_samples()[5]) == 559
      assert len(spark_dtree.get_node_samples()[11]) == 167
      assert len(spark_dtree.get_node_samples()[13]) == 121
      assert len(spark_dtree.get_node_samples()[16]) == 23
  
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 19 for calling a global function with example usage: test_get_node_samples(spark_dtree) without return types