code: def test_explain(self):
      t = self.t_env.from_elements(
          [(1, "Hi", "Hello")], ["a", "b", "c"]
      )
      result = (
          t.group_by(t.c)
          .select(t.a.sum, t.c.alias("b"))
          .explain(
              ExplainDetail.CHANGELOG_MODE, ExplainDetail.PLAN_ADVICE
          )
      )
      assert isinstance(result, str)
      self.assertGreaterEqual(
          result.find("== Optimized Physical Plan With Advice =="), 0
      )
      self.assertGreaterEqual(
          result.find(
              "advice[1]: [ADVICE] You might want to enable "
              "local-global two-phase optimization by configuring ("
              "'table.exec.mini-batch.enabled' to 'true', "
              "'table.exec.mini-batch.allow-latency' to a "
              "positive long value, 'table.exec.mini-batch.size' "
              "to a positive long value)."
          ),
          0,
      )
  
      result = (
          t.group_by(t.c)
          .select(t.a.sum, t.c.alias("b"))
          .explain(ExplainDetail.JSON_EXECUTION_PLAN)
      )
      assert isinstance(result, str)
      try:
          json.loads(result.split("== Physical Execution Plan ==")[1])
      except:
          self.fail(
              "The execution plan of explain detail is not in json format."
          )
  
imports: import json
  from pyflink.testing.test_case_utils import PyFlinkStreamTableTestCase
  from pyflink.table.explain_detail import ExplainDetail
label_desc: Use image node_id 1 for calling the StreamTableExplainTests obj's underlying member method code with example usage: obj.test_explain() without return types