code: def test_cohort_list_serialization(self):
      cohort_filter_1 = CohortFilter(
          method=CohortFilterMethods.METHOD_LESS, arg=[65], column="age"
      )
      cohort_1 = Cohort(name="Cohort New")
      cohort_1.add_cohort_filter(cohort_filter_1)
  
      cohort_2 = Cohort(name="Cohort Old")
      cohort_2.add_cohort_filter(cohort_filter_1)
  
      cohort_list = [cohort_1, cohort_2]
      json_str = json.dumps(
          cohort_list, default=cohort_filter_json_converter
      )
  
      assert "Cohort Old" in json_str
      assert "Cohort New" in json_str
      assert CohortFilterMethods.METHOD_LESS in json_str
      assert "[65]" in json_str
      assert "age" in json_str
  
imports: import json
  import pandas
  import pytest
  from raiutils.cohort import ClassificationOutcomes, Cohort, CohortFilter, CohortFilterMethods, cohort_filter_json_converter
  from raiutils.exceptions import UserConfigValidationException
label_desc: Use image node_id 1 for calling the TestCohortList obj's underlying member method code with example usage: obj.test_cohort_list_serialization() without return types